Croagunk

When this Pokémon enters battle, if one of its opponents has a move that is super effective against it, self destruct, explosion, or a one-hit knockout move, all participating trainers are notified. The move itself is not revealed; only that there is such a move. Moves that inflict typeless damage, such as future sight, and moves of variable type, such as hidden power, count as their listed types. counter, metal burst, mirror coat, and one-hit KO moves to which this Pokémon is immune do not trigger this ability.