Rivalry
About the ability
Rivalry is an ability introduced in generation 4.
18 Pokémon can have this ability, such as Nidoran F, Nidorina, Nidoqueen, Nidoran M and Nidorino. For 4 of them it is the hidden ability, usually obtained from events, raids or breeding.
Official effect
Increases damage inflicted to 1.25× against Pokémon of the same gender, but decreases damage to 0.75× against the opposite gender.
Nidoran F
Nidorina
Nidoqueen
Nidoran M
Nidorino
Nidoking
Shinx
Luxio
Luxray
Axew
Fraxure
Haxorus
Litleo
Pyroar
Beautifly
Pidove
Tranquill
Unfezant