Plantera

Plantera is a Hardmode Boss that can be fought after The Destroyer, Skeletron Prime, and The Twins have been defeated.

Summoning
After all 3 of the mechanical bosses have been defeated, one or more Plantera's Bulbs will appear somewhere in the Underground Jungle. Destroying one of these bulbs requires a Pickaxe or a Drill, and upon doing so, Plantera will spawn.

First stage
Plantera creeps after the player constantly firing seeds and flower petals directly at the player. As Plantera becomes damaged, it will fire more and more rapidly, and begin to spit large, bouncing spiked balls at the player which continue to bounce around the Jungle for a while before disappearing. At this stage, it is recommended that the player avoid cramped spaces to avoid the spike attack and allow sufficient room to dodge.

Second stage
Once Plantera is brought down to half its original health it will change to its second form, with its pink bud falling away to reveal a thorn-filled mouth. It moves quicker and primarily attempts to make physical contact rather than fire ranged attacks. It also sprouts mouths (called "Plantera's Tentacles") in all directions, as well as releases floating pink spores that drift toward the player (similar to the spores released by the Giant Fungi Bulb). Although the tentacles don't actively seek after the player, it is very dangerous to get close to Plantera in this stage.

Enraged stage
Plantera only becomes "enraged" if it follows the player out of the Underground Jungle, for instance to the surface. This causes it to gain significantly more damage and movement speed, and will attempt to remain directly on top of the player, causing constant damage.

Aftermath
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. A Temple Key drops each time Plantera is defeated thereafter.

The Temple Key allows access to the Lihzahrd Temple and Golem Boss, who drops Beetle Husk for crafting Beetle armor. In addition, the Temple Key can be combined with Dungeon Key Molds to craft keys for access to Dungeon Chests.

The Cyborg NPC becomes available, and the Truffle begins selling the Autohammer, used to craft Shroomite Bars for Shroomite armor and other endgame items. The Traveling Merchant will begin selling the Pulse Bow.

New, more difficult enemy types will begin to spawn in the Dungeon, which drop new weapons, accessories, and other useful items. Dungeon Spirits will begin to appear when Dungeon enemies are slain, which drop Ectoplasm, a new crafting material that offers access to the Pumpkin Moon and Frost Moon events, as well as the Spectre armor and tool sets.

Tips

 * Excavate a sizeable area to allow easier dodging before summoning Plantera.
 * Plantera's Bulb can spawn in player-made Jungle Biomes, which can provide a slightly easier way to fight Plantera.
 * Line up 2 teleporters ~50 blocks away from each other in two small separate rooms with a tiny hole. When Plantera is summoned, fire at it using a Megashark or Clockwork Assault Rifle. When it gets too close, teleport to the other room.
 * To find Plantera's Bulbs more easily, press M (for the map). Zoom in and look for a pink/purple rectangle. Put your mouse over the rectangle and it should say Plantera's Bulb.
 * Narrow Passages slow Plantera as it takes more time for it to grip the surrounding terrain. Use of the Death Sickle in the narrow passages will result in up to 3,000 max damage in a 30-40 tile tunnel.
 * If you have already beaten the Golem, the Stynger is very effective against Plantera.
 * Using a golden shower may be useful as it lowers its defense.
 * Using Dart traps or Super dart traps is also a good tactic

Trivia
It looks like iddings.
 * The name "Plantera" is a word play of the American metal band Pantera, which is Redigit's girlfriend's favorite band.
 * Plantera drops "The Axe", which looks similar to the Washburn and Dean electric guitars often used by late Pantera guitarist Dimebag Darrell.
 * Plantera's boss music features heavy electric guitar use.
 * This boss bears a resemblance to Kalle Demos from The Legend Of Zelda: The Wind Waker.

History

 * When killed for the first time the message is now "Screams are echoing from the dungeon..."