Straxus

Straxus was a Decepticon warlord in Earth year 1985, left there by Lord Jhiaxus when he left to lead the Second Generation Decepticons. Straxus was a petty tyrant, armed with an energo-ax, and who could transform into a devastating flying cannon.

Straxus' favored form of execution for Autobots was to dump them in the Smelting Pool, wherein they painfully melted to slag over a period of days. His reign was eventually ended by Blaster, when he was destroyed by the energies of the malfunctioning Space Bridge.

Marvel U.K.

Straxus's head survived. It was also revealed he had assassinated Megatron's successor as Decepticon leader to achieve his position. He continued on as commander, despite being just a head, until Megatron briefly returned to Cybertron, when they decided to cooperate.

They fed the Autobots misinformation that Optimus Prime, who had also arrived on Cybertron, was an impostor. However, when their deception was revealed and Optimus came to lead the Wreckers to a series of victories, Straxus and Megatron's alliance began to sour. Ultimately, Straxus used a device in an attempt to take over Megatron's mind- afterward, his head was destroyed. The attempt essentially failed, first causing Megatron and Straxus' minds to mesh, and then causing Megatron to reject Straxus' personality entirely. Megatron then lost all memory of the incident.

Straxus' mind took up residence in a duplicate of Megatron, which was sent to Earth, appearing beneath London. However, Straxus' personality was submerged, and the duplicate believed it was the real Megatron. Straxus' mind made a later attempt to take over the duplicate's body, but failed. When the duplicate later realized he was a fake, he destroyed himself rather than risk Straxus' possible victory.