Plantera

Plantera is a Hardmode boss. After at least one of either The Destroyer, Skeletron Prime, or The Twins has been defeated, one or more Plantera's Bulb's will appear somewhere in the Underground Jungle and the message "The jungle grows restless" appears. Destroying one of these bulbs, 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. Plantera's second form will also release floating pink spores that will slowly drift after the player, similar to the spores released by the Giant Fungi Bulb enemy.

If Plantera is taken out of the Jungle or to the surface, the AI will change dramatically. Once "enraged", Plantera gains significally increased damage and movement speed, and tends to sit directly on top of the player, causing constant damage. It does, however, still have to "grapple" walls with its vines, so having a tall enough arena would still allow a player to combat it on the surface.

When Plantera is defeated for the first time it will always drop a Grenade Launcher with Rocket I's for ammo, as well as the Temple Key. The Pygmy Staff and the Seedling also have a chance to drop. From the second time onward the drops become randomized.

Tips

 * It is worth the time to excavate land to make the boss much easier to dodge. Just note that the floor of your land probably will be covered with spiky balls that the boss spawns.
 * Plantera's Bulb can spawn in player made jungle biomes. This could prove as a good way to fight Plantera in a more controlled environment, away from jungle mobs, hazards, etc.
 * If you are planning to fight it but you are guessing you will die a lot, a trick is to get some thing like the Staff of the Frost Hydra to place and keep doing damage to it (Especially when it says "You have been slain")
 * Another method, which exploits Plantera's slowness, is to line up 2 teleporters ~50 blocks away from each other in two small separate rooms with a tiny hole. When Plantera is summoned, use a Megashark or Clockwork Assault Rifle to attack Plantera, and when he comes too close, teleport to the other room.

Trivia

 * The name "Plantera" is a parody of the American thrash metal band Pantera. The name originated from Pantera as this 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.
 * Plantera's boss music also consists of heavy usage of electric guitar, the basis of metal music.