Plantera

Plantera is a Hardmode boss. After at least one of either The Destroyer, Skeletron Prime, or The Twins has been defeated, a pink bulb will appear somewhere in the Underground Jungle. Destroying this bulb, which requires a Pickaxe or a Drill will summon Plantera.

The fight against Plantera takes place in two parts. In the first part Plantera will chase the player around the jungle, using its hooks to move around. In addition, Plantera will fire thorns at the player, as well as spitting out the occasional bouncy spiky ball.

Once Plantera is brought down to half health it will change form, the pink bud falling away to reveal a thorn-filled mouth. In this second form it retains its previous attacks, but will begin to move around quicker and more erratically, as well as sprouting a number of tentacle mouths which stretch outward on thin strands, similar to the Wall of Flesh's "Hungry" minions, though the tentacles do not detach when damaged, instead simply being destroyed. Second form Plantera will also release floating pink spores that will slowly drift after the player, similar to the spores released by the Giant Fungi Bulb enemy.

When Plantera is defeated for the first time it will always drop a Grenade Launcher with Rocket Is for ammo, as well as the Temple Key. From the second time onward the drops become randomized.

Trivia

 * The name "Plantera" is a parody of the American thrash metal band Pantera. It was named as thus because Pantera is Redigit's girlfriend's favorite band.
 * Plantera also drops "The Axe", which looks similar to the Washburn and Dean electric guitars often used by the late Pantera guitarist Dimebag Darrell. It could also be a reference to Marceline's Axe Bass from Adventure Time.
 * Plantera's boss music also consists of heavy usage of electric guitar, the basis of metal music.