Megastar

The Megastar was the Predacon starship and mobile command center. It was equipped with transwarp cells and also capable of moving underwater and underground; the versatile craft was constantly on the move to avoid detection by Autobots. The ship had a throne room for Megatron, living quarters for the crew, energon smelters, and special vats for converting other energy sources into energon. The ship's arsenal included missiles and beam weapons, and it also had a shield that would reflect incoming beam weapons back at attackers; with this technology the huge vessel was able to defeat even the hitherto-undefeated Omega Prime.

The Megastar's most obvious physical characteristics were its two huge humanoid arms, one of which ended in a five-fingered fist, the other in a two-pronged claw. During a heated battle, Galvatron expanded until he was able to graft his hand mode onto one of the Megastar's arms; thus augmented, the ship was able to brawl Fortress Maximus into an apparent stalemate. However, Maximus' tremendous firepower was enough to apparently destroy the Megastar--it was last seen bursting into flames and crashing and sinking beneath a lake ("Galvatron's Revenge"). So much for fisting.

Oddities
The Spychangers battled against the Megastar in "Mirage's Betrayal", yet many episodes later when they encounter the ship again in "Surprise Attack" they appear to have no memory of it and are, well, surprised!