Galaxikhan

In 1958, members of the then-fledgling M-Force were called to investigate a series attacks by electricity-devouring snakelike creatures that have sense earned the name "Electric Linguine." After dispatching the killer pasta, the M-Forcers followed its trail back to a crashed spacecraft, where they found tracks that appeared to belong to a 30' tall lizard-like being.
While the monster hunters followed the trail of thier new quarry, the monster itself razed the town of Carlton California before setting out for San Francisco. The scope of the damage and eyewitness reports suggested the creature was much larger than first expected. This mystery was solved soon enough when it was observed that the creature grew as it fed on electrical energy from the power grid. By the time it got to San Francisco, the creature was massive.
The day before, only lunatics and children believed in monsters. Then one day the whole country watched a gang of those aforementioned lunatics defeat a giant space lizard on national TV. One the world admitted that a monster from space could attack San Francisco, people were forced to reconsidere some of the other things they'd written off as impossible. Despite only living a few days on Earth, Galaxikhan change the world.

Galaxikhan first appeared in the Galaxikhan Attacks! adventure for M-Force. The adventure (and M-Force) are currently out of print.