gastrodon
Generation IV · #0423 — Sea Slug Pokémon
Gastrodon, known as the Sea Slug Pokémon, is a Water/Ground-type creature introduced in Generation IV that represents the evolved form of Shellos. With a National Pokédex number of #423, this remarkable Pokémon showcases a fascinating duality through its two regional forms—the West Sea and East Sea variants—each adapted to different ecosystems within the Sinnoh region. The West Sea form, characterized by its pink underside and brown mantle adorned with three pink spots on each side, exemplifies the adaptation of this species to its specific oceanic environment. Despite its seemingly fragile, boneless composition, Gastrodon possesses an impressive base HP stat of 111, making it one of the more durable Water-type Pokémon for its generation, complemented by respectable Special Attack (92) and Special Defense (82) stats that enable it to function effectively as both an offensive and defensive force.
Base Stats
Height
0.9m
Weight
29.9kg
Category
Sea Slug Pokémon
Gender
Male 50% / Female 50%
Color
purple
Shape
squiggle
Abilities
Prevents a held item from being removed by other Pokémon.
Redirects single-target water moves to this Pokémon where possible. Absorbs Water moves, raising Special Attack one stage.
Strengthens rock, ground, and steel moves to 1.3× their power during a sandstorm. Protects against sandstorm damage.
Gastrodon Biology & Physical Characteristics
Gastrodon is a gastropod-inspired Pokémon with a distinctly slug-like morphology, featuring a rounded head and a mantle that covers the upper portion of its body. The West Sea form displays a pair of large, upward-curving tentacles on its head and smaller, straighter tentacles on its neck, giving it a unique silhouette compared to its East Sea counterpart. A characteristic yellow stripe runs along the edge of its mantle, through its two lower eyes, and around the back of its head, creating distinctive facial markings that include a forehead marking resembling a third eye. The West Sea form's body is supported by six stubby legs and covered in a pink underside with a brown dorsal mantle surface. Most notably, Gastrodon possesses two lumps on its back that resemble cerata found on real-life sea slugs, serving as remnants of its ancestral biology. The Pokédex entries reveal a profound evolutionary history: the species once possessed a complete protective shell covering its entire back, but through countless generations of adaptation, only cellular traces of this ancient armor remain, a testament to the dramatic evolutionary changes this lineage has undergone.
Pokedex Numbers
Training
Breeding
Gastrodon Breeding, Gender Ratio & Egg Groups
Gastrodon exhibits a perfectly balanced gender ratio of 50% male and 50% female, making gender-based breeding strategies equally viable for both sexes without any biological predisposition toward one form or another. This Pokémon belongs to two egg groups—Water 1 and Indeterminate—providing flexible breeding options with a wide variety of compatible partner Pokémon species. The Water 1 egg group designation aligns with Gastrodon's aquatic nature and allows it to breed with numerous other water-dwelling Pokémon that share this classification, while the Indeterminate group membership reflects the species' unique, somewhat alien biology that doesn't fit neatly into traditional reproductive categories. Gastrodon has a base friendship value of 70, indicating a moderate predisposition toward bonding with trainers, and it requires twenty egg cycles to hatch from an egg—equivalent to approximately 4,884 to 5,140 steps of travel. Breeding pairs will pass down the West Sea or East Sea form determination based on the female's form, a useful trait for trainers seeking to propagate specific variants without needing to evolve Shellos in different geographic locations.
Sprites
TMs & HMs
tm01
lets go pikachu lets go eevee
tm02
crystal
tm02
gold silver
tm03
crystal
tm03
gold silver
tm03
ruby sapphire
tm03
platinum
tm03
firered leafgreen
tm03
heartgold soulsilver
tm03
diamond pearl
tm03
emerald
tm03
xd
tm03
colosseum
tm03
lets go pikachu lets go eevee
tm05
lets go pikachu lets go eevee
tm06
yellow
tm06
gold silver
tm06
red blue
tm06
crystal
tm06
emerald
+706 more TMs/HMs
Forms
westDefault
eastgastrodon's Evolution Chain
Gastrodon Evolution, Mega Evolution & Special Forms
Gastrodon evolves from Shellos at level 30, marking a significant transformation in both appearance and capability for this Water-type line. The evolution process involves a substantial increase in body mass and the development of the distinctive lumps on the back that characterize the mature form, along with enhanced musculature that supports improved combat statistics. Notably, Gastrodon does not possess a Mega Evolution form, nor does it have any further evolution branches, making it the terminal form of its evolutionary line. However, the West Sea form's evolution from Shellos is geographically determined—trainers who evolve their Shellos on the western side of Sinnoh's mountain range will obtain the West Sea variant with its characteristic pink and brown coloration, while those evolving on the eastern side receive the blue and green East Sea form. This geographical determination of form represents an interesting gameplay mechanic that encourages players to engage with different regions of the game world and rewards exploration with distinct Pokémon variations.
Where to Find
sinnoh route 222
sinnoh
+6 more
sinnoh route 218
sinnoh
+10 more
sinnoh route 221
sinnoh
+4 more
sinnoh sea route 230
sinnoh
sinnoh route 224
sinnoh
+5 more
fuego ironworks
sinnoh
+8 more
canalave city
sinnoh
pastoria city
sinnoh
valley windworks
sinnoh
sinnoh route 205
sinnoh
sinnoh route 212
sinnoh
sinnoh route 213
sinnoh
poni wilds
alola
+3 more
exeggutor island
alola
+1 more
ancient poni path
alola
+3 more
poni breaker coast
alola
Gastrodon Behaviour and Natural Habitat
West Sea Gastrodon thrives in shallow tidal pools and coastal waters on the western side of Sinnoh's mountain range, where it has adapted to distinct environmental conditions that differ from its East Sea relatives. Despite its apparent vulnerability due to its boneless, pliable body, this Pokémon possesses extraordinary regenerative capabilities that represent one of its most remarkable biological features. According to Pokédex documentation, if any part of Gastrodon's body is torn off—whether by predatory Fish Pokémon or other threats—the missing segments will regenerate completely within just a few hours, allowing the creature to recover from significant injuries with remarkable efficiency. When threatened by natural predators, Gastrodon employs an interesting defensive strategy: it oozes a distinctive purple fluid that both obscures its position and aids its escape, demonstrating sophisticated antipredator behavior despite its seemingly defenseless nature. This combination of rapid regeneration and chemical defense mechanisms has allowed West Sea Gastrodon to establish itself as a successful inhabitant of its tidal pool ecosystem, where it feeds on smaller aquatic organisms and marine vegetation.
Pokedex Entries
It has a pliable body without any bones. If any part of its body is torn off, it grows right back.
It apparently had a huge shell for protection in ancient times. It lives in shallow tidal pools.
Long ago, its entire back was shielded with a sturdy shell. There are traces of it left in its cells.
When its natural enemy attacks, it oozes purple fluid and escapes.
Long ago, its entire back was shielded with a sturdy shell. There are traces of it left in its cells.
Long ago, its entire back was shielded with a sturdy shell. There are traces of it left in its cells.
When its natural enemy attacks, it oozes purple fluid and escapes.
It apparently had a huge shell for protection in ancient times. It lives in shallow tidal pools.
When its natural enemy attacks, it oozes purple fluid and escapes.
It apparently had a huge shell for protection in ancient times. It lives in shallow tidal pools.
It has strong regenerative capabilities. Even if parts of it are bitten off by fish Pokémon, it will return to normal within a few hours.
Long ago, it had a shell on its back. There’s now a vestigial plate on its back that’s hard but thin.
Plankton, invisible to the naked eye, is its main food source. It comes onto the land periodically, but the reason for this is not known.
Their shape and color change, depending on their environment and diet. There are many of them at beaches where the waves are calm.
Its search for food sometimes leads it onto land, where it leaves behind a sticky trail of slime as it passes through.
The softness of its body helps disperse the force of impacts, so although its body is uncommonly squishy, it’s also surprisingly resilient.
Eats beach sand for nourishment. Should one Gastrodon encounter another of a different color, a fierce battle will inevitably ensue.
Gastrodon Name Origin & Design Inspiration
The West Sea Gastrodon's design draws heavily from real-world marine gastropods, particularly sea slugs and nudibranchs, which are known for their colorful appearances and diverse defensive mechanisms. The name 'Gastrodon' is derived from 'gastro-' (referring to the stomach or belly) and '-odon' (tooth), though the creature itself lacks teeth entirely, possibly referencing its shell-less nature where internal structures are more prominent. In Japanese, Gastrodon is called Tritodon, likely referencing Triton from Greek mythology—a messenger god of the sea depicted carrying a conch shell—which aligns thematically with the species' oceanic nature and its ancestral relationship with shelled creatures. The West Sea form's pink and brown coloration may reflect real sea slug species found in temperate or western ocean regions, while the two tentacle pairs distinguish it visually from its East Sea counterpart. The yellow striping pattern that runs across the creature's body serves both an aesthetic and functional purpose in Pokémon design, creating visual continuity with its pre-evolution Shellos while providing distinctive identification markers that trainers can use to differentiate between the two forms.
Learnable Moves
Gastrodon can learn 79 moves:
Move | Type | Cat. | Power | Acc. | PP |
|---|---|---|---|---|---|
| amnesia | psychic | Status | — | — | 20 |
| ancient power | rock | Special | 60 | 100 | 5 |
| attract | normal | Status | — | 100 | 15 |
| blizzard | ice | Special | 110 | 70 | 5 |
| block | normal | Status | — | — | 5 |
| body slam | normal | Physical | 85 | 100 | 15 |
| brine | water | Special | 65 | 100 | 10 |
| bulldoze | ground | Physical | 60 | 100 | 20 |
| captivate | normal | Status | — | 100 | 20 |
| chilling water | water | Special | 50 | 100 | 20 |
| confide | normal | Status | — | — | 20 |
| curse | ghost | Status | — | — | 10 |
| dig | ground | Physical | 80 | 100 | 10 |
| dive | water | Physical | 80 | 100 | 10 |
| double team | normal | Status | — | — | 15 |
| earth power | ground | Special | 90 | 100 | 10 |
| earthquake | ground | Physical | 100 | 100 | 10 |
| endure | normal | Status | — | — | 10 |
| facade | normal | Physical | 70 | 100 | 20 |
| flash | normal | Status | — | 100 | 20 |
| frustration | normal | Physical | — | 100 | 20 |
| giga impact | normal | Physical | 150 | 90 | 5 |
| hail | ice | Status | — | — | 10 |
| harden | normal | Status | — | — | 30 |
| headbutt | normal | Physical | 70 | 100 | 15 |
| helping hand | normal | Status | — | — | 20 |
| hidden power | normal | Special | 60 | 100 | 15 |
| hydro pump | water | Special | 110 | 80 | 5 |
| hyper beam | normal | Special | 150 | 90 | 5 |
| ice beam | ice | Special | 90 | 100 | 10 |
| icy wind | ice | Special | 55 | 95 | 15 |
| infestation | bug | Special | 20 | 100 | 20 |
| liquidation | water | Physical | 85 | 100 | 10 |
| memento | dark | Status | — | 100 | 10 |
| mud bomb | ground | Special | 65 | 85 | 10 |
| mud shot | ground | Special | 55 | 95 | 15 |
| mud sport | ground | Status | — | — | 15 |
| mud slap | ground | Special | 20 | 100 | 10 |
| muddy water | water | Special | 90 | 85 | 10 |
| natural gift | normal | Physical | — | 100 | 15 |
| pain split | normal | Status | — | — | 20 |
| protect | normal | Status | — | — | 10 |
| rain dance | water | Status | — | — | 5 |
| recover | normal | Status | — | — | 5 |
| rest | psychic | Status | — | — | 5 |
| return | normal | Physical | — | 100 | 20 |
| rock blast | rock | Physical | 25 | 90 | 10 |
| rock slide | rock | Physical | 75 | 90 | 10 |
| rock smash | fighting | Physical | 40 | 100 | 15 |
| rock tomb | rock | Physical | 60 | 95 | 15 |
| round | normal | Special | 60 | 100 | 15 |
| sand tomb | ground | Physical | 35 | 85 | 15 |
| sandstorm | rock | Status | — | — | 10 |
| scald | water | Special | 80 | 100 | 15 |
| secret power | normal | Physical | 70 | 100 | 20 |
| skitter smack | bug | Physical | 70 | 90 | 10 |
| sleep talk | normal | Status | — | — | 10 |
| sludge bomb | poison | Special | 90 | 100 | 10 |
| sludge wave | poison | Special | 95 | 100 | 10 |
| snore | normal | Special | 50 | 100 | 15 |
| snowscape | ice | Status | 0 | — | 10 |
| spikes | ground | Status | — | — | 20 |
| stealth rock | rock | Status | — | — | 20 |
| stomping tantrum | ground | Physical | 75 | 100 | 10 |
| stone edge | rock | Physical | 100 | 80 | 5 |
| strength | normal | Physical | 80 | 100 | 15 |
| string shot | bug | Status | — | 95 | 40 |
| substitute | normal | Status | — | — | 10 |
| surf | water | Special | 90 | 100 | 15 |
| swagger | normal | Status | — | 85 | 15 |
| tackle | normal | Physical | 40 | 100 | 35 |
| take down | normal | Physical | 90 | 85 | 20 |
| tera blast | normal | Special | 80 | 100 | 10 |
| toxic | poison | Status | — | 90 | 10 |
| water gun | water | Special | 40 | 100 | 25 |
| water pulse | water | Special | 60 | 100 | 20 |
| waterfall | water | Physical | 80 | 100 | 15 |
| weather ball | normal | Special | 50 | 100 | 10 |
| whirlpool | water | Special | 35 | 85 | 15 |
Gastrodon Competitive Battle Guide
In competitive Pokémon battles, West Sea Gastrodon serves as a viable defensive bulwark with its impressive 111 HP stat and respectable 82 Special Defense, making it particularly effective against special-attack-focused opponents. Its typing provides valuable resistances to Electric, Poison, and Rock-type moves while granting immunity to Electric-type attacks through the Storm Drain ability—one of its signature traits that not only blocks Water-type moves but actually redirects single-target Water moves to Gastrodon and raises its Special Attack by one stage when activated. This ability transforms Gastrodon into a capable answer to opposing Water-type threats, particularly Water Pokémon that rely on Water-type moves for coverage. The Sticky Hold ability offers alternative utility by preventing opponents from removing Gastrodon's held item, which can be strategically valuable when using items like assault vest or choice scarf. The hidden Sand Force ability provides a more offensive option in sandstorm-based team compositions, boosting Rock, Ground, and Steel-type moves to 1.3× their power while granting immunity to sandstorm damage. Gastrodon's move pool includes reliable options like Earthquake, Scald, and Recover, with a base Special Attack of 92 providing sufficient offensive pressure in competitive formats. Its relatively low Speed stat of 39 necessitates careful team building and support from items or abilities to function optimally, making it best suited to defensive cores rather than offensive threats.
Commonly Asked Questions About Gastrodon
What type is Gastrodon?
Gastrodon is a water and ground type Pokemon.
What does Gastrodon evolve from?
Gastrodon evolved from shellos.
What are Gastrodon's weaknesses?
Gastrodon is weak to grass and electric type moves.
Where can I find Gastrodon?
Gastrodon can be found in sinnoh route 222 (sinnoh), sinnoh route 218 (sinnoh) and sinnoh route 221 (sinnoh) and 13 other locations.
Gastrodon Cultural Impact & Franchise History
Gastrodon achieved significant cultural prominence within the Pokémon anime series through the character of Zoey, a main character and Pokémon Coordinator, who utilized a West Sea Gastrodon as a key member of her competitive team. Her Gastrodon's performances in Pokémon Contests showcased the species' elegance and capability, introducing the creature to a substantial audience and elevating its status within the franchise's popular media. The two regional forms of Gastrodon—West Sea and East Sea—have become iconic representations of the concept of environmental adaptation and regional variation within the Pokémon universe, predating the more extensive regional form mechanics introduced in later generations. The species' biological feature of being able to regenerate lost body parts has captured the imagination of players and lore enthusiasts, inspiring discussions about evolutionary adaptation and survival strategies in fictional ecosystems. Trading and battling communities frequently discuss Gastrodon's strategic applications in competitive formats, particularly its unique niche as a Water-type capable of absorbing Water-type attacks rather than being vulnerable to them. The creature's design has influenced subsequent Pokémon species with similar regional variations, establishing a template for location-based form differentiation that became increasingly prevalent throughout the franchise.
Where to Find Gastrodon in Every Pokémon Game
West Sea Gastrodon can be encountered in Sinnoh's water routes on the western side of the region's central mountain range, where trainers find its pre-evolution Shellos and can evolve them at level 30. In Pokémon Diamond and Platinum, this form appears in specific water areas corresponding to its western habitat designation, while Brilliant Diamond remakes maintain similar availability patterns for player convenience. Beyond its native Sinnoh region, Gastrodon appears in subsequent generations with varying availability: it returns in HeartGold and SoulSilver through specific water encounters, becomes available in the Alola region of Pokémon Sun and Moon (appearing in the Alola Pokédex as #0261), and receives new entries in more recent titles including Sword and Shield and Scarlet and Violet. The capture rate of 75 indicates moderate catchability with standard Poké Balls, making West Sea Gastrodon reasonably accessible to players without requiring specialized catching techniques or rare items. Trading between versions remains a viable method for obtaining the West Sea form in games where it doesn't naturally appear, particularly for players preferring this form over its East Sea counterpart. Event distributions have occasionally featured Gastrodon, including special Wonder Card distributions that have provided trainers with pre-evolved Shellos or evolved Gastrodon specimens with enhanced stats or rare abilities, offering alternative acquisition methods beyond standard in-game encounters.