Hoppin' Jack

The Hoppin' Jack is a Hardmode pumpkin-like enemy that will only appear at night during the Halloween seasonal event, or in Graveyards any time of year. He attacks by hopping towards the player in a manner identical to most Slimes. The difference, however, is that the lower on health he is, the quicker he becomes.

Notably, as Hoppin' Jack is actually a pumpkin that uses the Slime AI, he is not treated as a slime for most other purposes. Hoppin' Jack drops no Gel on death, will remain hostile to a player with Royal Gel equipped, and killing one is not necessary to earn the Gelatin World Tour or Slimer/King of Slimes  achievements.

Trivia

 * The name Hoppin' Jack is a reference to, a creature from British folklore.