Skeletron Prime

. The Skeletron Prime is a hardmode version of the Skeletron boss. It can be summoned with the Mechanical Skull.

Unlike Skeletron, it has four hands with different designs and attacks for each. His eyes are red, his mouth has a chomping animation and when he enters the mode where his head spins, his head grows spikes. The blood animation on the normal Skeletron is replaced with fire on Skeletron Prime.

Like Skeletron, Skeletron Prime must be defeated before the break of dawn; otherwise he will enter a permanent spin mode, and damage and defense will increase to 9999. Anyone still alive at this point will not likely remain so for long. To defeat Skeletron Prime it is enough to kill the Head.