Thick Fat
Halves Fire and Ice damage.
Pokémon with this ability
Seel
Dewgong
Snorlax
Marill
Azumarill
Miltank
Makuhita
Hariyama
Azurill
Spoink
Grumpig
Spheal
Sealeo
Walrein
Purugly
Munchlax
As a hidden ability
Not in the game yet
No Pokémon can be obtained with its hidden ability yet, so these are listed for reference.
Swinub
PiloswineAs of v0.77.1 · engine d7ff0bbe