Jack o'Cache puts pumpkins on certain mobs during Halloween, like Vanilla does
Showcased here are the Chicken Pumpkin and the Pig Pumpkin.
Showcased here is the Dragon Pumpkin.
Showcased here are the Sinister Pumpkin, Generic Pumpkin, Creeper Pumpkin and Slime Pumpkin.
Showcased here are the Sinister Jack o'Lantern, Generic Jack o'Lantern, Creep Jack o'Lantern and Goo Jack o'Lantern.