If a pokemon uses a physical move on Cofagrigus and obtains the ability mummy, and then switches, will it still have mummy when it switches back in?
>"When the user is attacked by a contact move, the opposing Pokémon's Ability is turned into Mummy as well. The affected Pokémon's Ability returns to normal when they are returned to their Poké Ball." -Bulbapedia
http://pokemondb.net/pokebase/44875/does-the-ability-mummy-stick-after-you-switch-out
