On paper, Gastrodon looks underwhelming. In practice, Storm Drain redirects Water moves and boosts its Sp. Atk — and that's the whole story. Water/Ground typing means Electric moves can't touch it, and only a single type hits it super-effectively. Known as the Sea Slug Pokemon.
Gastrodon's spread is anchored by HP, with balanced defenses backing it up. Speed is the clear weak point. Worth 2 HP EVs per KO, and the medium-fast 1M XP curve keeps leveling painless.
When it’s attacked, it gushes a purple liquid that’s not poisonous but makes Gastrodon’s meat bitter and inedible.
A relative of Shellder and Cloyster, this ocean dweller sometimes comes onto land in search of food.
Gastrodon Weakness
GoodGastrodon's Water/Ground typing leaves it vulnerable to Grass moves. Grass hits land at 4x, so they're the biggest threat. It shrugs off Electric-type attacks completely. It resists 4 types, giving it decent defensive coverage. Storm Drain grants an additional Water immunity, reshaping the matchup chart. With 111 HP and balanced defenses, Gastrodon can afford to eat a neutral hit or two.
Gastrodon is the evolved form of Shellos. Breeding produces Shellos eggs, and they're average hatch time. Evolving from Shellos gave Gastrodon the biggest boost in HP (+35), bringing the total to 475 stats.
How to Evolve
Breed with Gastrodon to get Shellos eggs easily from the Indeterminate and Water1 egg groups. Notable egg moves include Acid Armor, Amnesia, Brine and 13 more.
Modest nature gives Gastrodon the special lean it needs to trade hits effectively. Leftovers adds passive recovery each turn, max HP and Sp. Atk EVs split the difference, and the remaining moves punishes anything trying to wall it.
Best Build
Best Gastrodon Moveset
- Earth Power
- Ice Beam
- Scald
- Protect
Recommended Teammates
The natural movepool does the job, but Acid Armor and Amnesia from the egg pool give Gastrodon something extra. Pair those with Earthquake and Muddy Water for STAB and coverage across 7 types for reach, and the kit fills out nicely.
Level-Up Moves
TM Moves
Egg Moves
Tutor Moves
Transfer Moves
decent spawn rates for Gastrodon across 10 locations in late-game routes. Nothing complicated. Check the sorted list below, compare the top few options, and head to whichever is closest.
Where To Catch Gastrodon in Ultra Sun & Ultra Moon
The path to Gastrodon starts with Shellos at Lv. 41-45 via walking, surfing, and more encounters. 2 catchable stages total, with locations listed for each one below.
Step 1Catch ShellosSeafolk VillageUltra SunIn-game tradeLv.44LateCityTrade for (give Granbull)Seafolk VillageUltra MoonIn-game tradeLv.44LateCityTrade for (give Granbull)
Step 2Gastrodon ✓MODERATEAncient Poni PathUltra MoonSurfing on waterLv.41-4420%LateRouteMODERATEAncient Poni PathUltra SunSurfing on waterLv.41-4420%LateRouteMODERATEPoni Breaker CoastUltra SunSurfing on waterLv.41-4420%LateWaterMODERATEPoni Breaker CoastUltra MoonSurfing on waterLv.41-4420%LateWaterMODERATEAncient Poni PathUltra MoonGrassLv.41-4410%LateRouteMODERATEAncient Poni PathUltra SunGrassLv.41-4410%LateRouteMODERATEPoni WildsUltra SunGrassLv.41-4410%LateMODERATEPoni WildsUltra MoonGrassLv.41-4410%LateMODERATEExeggutor IslandUltra SunGrassLv.42-4510%LateWaterMODERATEExeggutor IslandUltra MoonGrassLv.42-4510%LateWateror evolve from Shellos (Step 1)
Don't let Gastrodon's 475 base stat total fool you. Storm Drain is what makes it tick — it punches way above its weight class. We rate it B-Tier as a trick room.
Watch for Roserade (Grass) when using Gastrodon. They all hit it super-effectively with STAB. Roserade is the most dangerous since Grass moves deal 4x damage. Only 1 weakness means fewer dedicated counters to worry about. At base 39 Speed, Gastrodon won't outrun any of these threats so switching to a resist is usually the safer play.
Shellos evolves into Gastrodon at level 30. Gastrodon is the fully evolved form. It sits at 475 BST in its evolved form.
Run Storm Drain on Gastrodon. It's the ability that defines how you build around it and the main reason it holds a competitive niche. Gastrodon also gets Sticky Hold and Sand Force, but they don't compare.
Gastrodon fills the trick room role. It's leaning toward the special side (base 92 Sp. Atk). Base 39 Speed is low. Priority moves or Trick Room are the way to go. And it's enough bulk to take a hit or two.
Gastrodon appears in 13 games, including Platinum, HeartGold & SoulSilver, and Diamond & Pearl.
Gastrodon first appeared in Diamond & Pearl and has been available in 13 games across 6 generations. Obtainable through wild encounters in most titles where it appears.
- Gen IY
Yellow - Gen IRB

Red & Blue - Gen IIGS

Gold & Silver - Gen IIC
Crystal - Gen IIIRS

Ruby & Sapphire - Gen IIIFRLG

FireRed & LeafGreen - Gen IIIE
Emerald - Gen IVPt
Platinum - Gen IVHGSS

HeartGold & SoulSilver - Gen IVDPDebut

Diamond & Pearl - Gen VBW

Black & White - Gen VB2W2

Black 2 & White 2 - Gen VIXY

X & Y - Gen VIORAS

Omega Ruby & Alpha Sapphire - Gen VIIUSUM

Ultra Sun & Ultra Moon - Gen VIISM

Sun & Moon - Gen VIILGPE

Let's Go Pikachu & Eevee - Gen VIIISwSh

Sword & Shield - Gen VIIIPLA
Legends: Arceus - Gen VIIIBDSP

Brilliant Diamond & Shining Pearl - Gen IXSV

Scarlet & Violet - Gen IXLZA
Legends: Z-A