Generation Iii
Hyper Cutter
Prevents ATTACK reduction.
Detailed Effect
This Pokémon's Attack cannot be lowered by other Pokémon. This ability does not prevent any Attack losses other than stat modifiers, such as the Attack cut from a burn. This Pokémon can still be passed negative Attack modifiers through Heart Swap or Power Swap.
Pokémon With Hyper Cutter
12 canonical Pokémon forms can have this Ability.

Krabby 
Kingler
Pinsir
Gligar 
Mawile
Trapinch
Corphish
Crawdaunt
Gliscor
Crabrawler 
Crabominable
Kingler Gmax