Cacophony

This Pokémon is immune to moves with the Sound-based flag.

Heal Bell is unaffected. Uproar still prevents this Pokémon from sleeping. This Pokémon can still receive a Perish Song counter through Baton Pass, and will retain a Perish Song counter if it acquires this ability after Perish Song is used.

Howl, Roar of Time, Sonic Boom, and Yawn are not flagged as sound-based.

(Cacophony is an actual ability programmed into the third-generation Pokémon games by Game Freak and simply never used; it was removed from the fourth-generation games. It's unclear why they discarded Cacophony, as after all there are plenty of other duplicate abilities. As such, Cacophony has been used here wherever it seems more appropriate than Soundproof.)

The wild encounter rate is halved while this Pokémon is first in the party.