The monstruous entity of Chrono Trigger. Apparently, an immense cross of a pine cone and a hedgehog, Lavos arrived from the outer space and buried itself underground 65 million years ago. It stayed there, gathering energy from the beings of the planet, briefly summoned by Queen Zeal at the year 10000 BC and the Magus at 600 AD.

Lavos' biology is not fully known. 65 millions of gathered energy enable it to warp time and space, and turn it against any that are foolish enough to challenge its plan.

In the normal time continuum, Lavos will surface at 1999 AD, destroy the world and the human civilization, and create spawns of its own to populate other planets...

Quoted from IRC: I'd say the fact that Lavos is really a chicken in a space suit is reason enough to hate the bastard.