Thick Fat (ability)

Effect

Thick Fat reduces the damage taken from Fire-type and Ice-type moves by 50%.

Interestingly, many Pokémon possessing this ability already take reduced damage from those types. A Dewgong or Walrein with Thick Fat would take ¹⁄₈ normal damage when hit by an Ice-type move.

Game descriptions

Ruby/Sapphire FireRed/LeafGreen Emerald	Heat-and-cold protection.
Diamond/Pearl Platinum	Raises resistance to Fire- and Ice-type moves.
HeartGold/SoulSilver	Ups resistance to Fire- and Ice-type moves.
Black/White Black 2/White 2	Ups resistance to Fire- and Ice-type moves.
X/Y	Boosts resistance to Fire- and Ice-type moves.
O.Ruby/A.Sapphire	Boosts resistance to Fire- and Ice-type moves.
Sun/Moon Ultra Sun/Ultra Moon	The Pokémon is protected by a layer of thick fat, which halves the damage taken from Fire- and Ice-type moves.

Pokémon with Thick Fat

#	Name	2^nd ability	Hidden ability
003	Venusaur Mega Venusaur	—	—
086	Seel	Hydration	Ice Body
087	Dewgong	Hydration	Ice Body
143	Snorlax	Immunity	Gluttony
183	Marill	Huge Power	Sap Sipper
184	Azumarill	Huge Power	Sap Sipper
241	Miltank	Scrappy	Sap Sipper
296	Makuhita	Guts	Sheer Force
297	Hariyama	Guts	Sheer Force
298	Azurill	Huge Power	Sap Sipper
325	Spoink	Own Tempo	Gluttony
326	Grumpig	Own Tempo	Gluttony
363	Spheal	Ice Body	Oblivious
364	Sealeo	Ice Body	Oblivious
365	Walrein	Ice Body	Oblivious
432	Purugly	Own Tempo	Defiant
446	Munchlax	Pickup	Gluttony

Thick Fat as a hidden ability

#	Name	Other abilities
019	Rattata Alolan Rattata	Hustle Gluttony
020	Raticate Alolan Raticate	Hustle Gluttony
220	Swinub	Oblivious Snow Cloak
221	Piloswine	Oblivious Snow Cloak
473	Mamoswine	Oblivious Snow Cloak
498	Tepig	Blaze
499	Pignite	Blaze