Flash Fire
Introduced in Generation III
This Pokémon is immune to Fire-type moves. Once this Pokémon has been hit by a Fire move, its own Fire moves will inflict 1.5× as much damage until it leaves battle. This ability has no effect while the Pokémon is frozen. The Fire damage bonus is retained even if the Pokémon is frozen and thawed or the ability is lost or disabled. Fire moves will ignore this Pokémon's Substitute. This ability takes effect even on non-damaging moves, i.e. Will-O-Wisp.
“If hit by a Fire-type move, the Pokémon absorbs the flames and uses them to power up its own Fire-type moves.”
As a regular ability 22
#0037
Vulpix
Fire
#0038
Ninetales
Fire
#0058
Growlithe
Fire
#0058
Hisuian Growlithe
FireRock
#0059
Arcanine
Fire
#0059
Hisuian Arcanine
FireRock
#0077
Ponyta
Fire
#0078
Rapidash
Fire
#0136
Flareon
Fire
#0228
Houndour
DarkFire
#0229
Houndoom
DarkFire
#0485
Heatran
FireSteel
#0607
Litwick
GhostFire
#0608
Lampent
GhostFire
#0609
Chandelure
GhostFire
#0631
Heatmor
Fire
#0850
Sizzlipede
FireBug
#0851
Centiskorch
FireBug
#0851
Gigantamax Centiskorch
FireBug
#0935
Charcadet
Fire
#0936
Armarouge
FirePsychic
#0937
Ceruledge
FireGhost