Espurr

Put 2 damage counters on 1 of your opponent’s Pokémon. If your opponent’s Pokémon is Knocked Out by this attack, take another turn after this one. (Skip Pokémon Checkup.) If 1 of your Pokémon used Yoga Loop during your last turn, this attack can’t be used.

It uses sound waves to communicate with others of its kind. People and other Pokémon species can't hear its cries of warning.