Generation Iii
Flash Fire
Powers up if hit by fire.
Detailed Effect
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.
Pokémon With Flash Fire
29 canonical Pokémon forms can have this Ability.
Regular Ability 22 Pokémon
#0037
Vulpix
#0038
Ninetales
#0058
Growlithe
#0059
Arcanine
#0077
Ponyta
#0078
Rapidash
#0136
Flareon
#0228
Houndour 
#0229
Houndoom 
#0485
Heatran 
#0607
Litwick 
#0608
Lampent 
#0609
Chandelure 
#0631
Heatmor
#0850
Sizzlipede 
#0851
Centiskorch 
#0935
Charcadet
#0936
Armarouge 
#0937
Ceruledge 
#10220
Centiskorch Gmax 
#10229
Hisuian Growlithe 
#10230
Hisuian Arcanine 
Vulpix
Ninetales
Growlithe
Arcanine
Ponyta
Rapidash
Flareon
Houndour
Houndoom
Heatran
Litwick
Lampent
Chandelure
Heatmor
Sizzlipede
Centiskorch
Charcadet
Armarouge
Ceruledge
Centiskorch Gmax
Hisuian Growlithe
Hisuian Arcanine 
Cyndaquil
Quilava
Typhlosion
Rolycoly
Carkol
Coalossal
Coalossal Gmax