Plantera Seedling

The Plantera Seedling is a Master Mode-exclusive pet dropped by Plantera, with a 1/4 (25%) chance to drop. Upon use, it summons a baby Plantera pet.

The Mud Bud is a similar item, but it spawns a different pet and is instead sold by the Zoologist after defeating Plantera.

Trivia

 * The buff tooltip is likely a reference to the 1960 cult horror film (and more notably its 1986 remaster) , in which the main character finds a talking alien plant that grows big and takes over the world. The tooltip “What exactly does it eat, anyway?” references how said plant only eats human blood.