Krampus

Krampus is a Hardmode, post-Plantera enemy that appears during the Frost Moon event. Its first appearance in the event is on Wave 8. Killing a Krampus rewards 18 points during the Frost Moon.

Trivia

 * Krampus is known in Alpine folklore as the evil version of Santa Claus (or a companion of Saint Nicholas), punishing or capturing children who misbehave during the Christmas season.