Pumpking

The  is a hardmode boss that spawns during the Pumpkin Moon. It first spawns at wave 7, and it seems to have a AI similar to Skeletron (including having a similar difficulty). It has two lengthy arms, each with a large scythe. These hands act much like Skeletron's hands, but they are indestructible.

It is considered the final boss of the Pumpkin Moon, and subsequent waves after its appearance increase the number of mobs. There can be a large number of Pumpkings attacking at once in the later stages (up to 7 at a time).

It is recommended that multiple players take on this boss during the Pumpkin Moon since the monsters can be quite overwhelming and difficult to deal with at the same time.

Behavior
Its attack pattern depends on the way its face looks; it will change its face in a random manner (unaffected by taking damage). Note that which face the Pumpking will change to is random, so be prepared for anything!
 * 1) His first face will be a typical jack 'o lantern style evil grin, and he will attack as Skeletron would, so the same strategies apply.
 * 2) His second face will look like he is annoyed, with his mouth in an O shape. He will attack you with his hands and will spit Greek fire similar to Mourning Wood.
 * 3) His third face will look similar to his second face, but with not such a wide mouth and half closed eyes. In this phase he willl use flaming blades that act like the Demon Scythe spell, but are much more damaging.
 * 4) When all players in the map die at one point in time, Pumpking will flee just like the other bosses and a new one will appear in the next wave.

Trivia

 * He is like a second boss from The Legend of Zelda: Oracle of Ages, he also switches between 4 faces!