Mud Bud

The Mud Bud is a pet summon item that is sold by the Zoologist after defeating Plantera. It summons Plantero, which resembles a miniature version of Plantera, that will follow the player around. When the player moves above or away at a certain speed, Plantero will fly after the player referencing Plantera's second form.

The Plantera Seedling is a similar item, however it is exclusive to Master Mode, and is directly dropped by Plantera upon defeat with a 1/4 (25%) chance.

Trivia

 * This was stated to be Red's favourite pet.