Game: Chrono Trigger
What Makes Him Bad: Mingling with escaping cells to transplant copies of himself throughout the universe? Bad boy.
What Makes Him Cool: Unequivocally menacing looks.

The space parasite—ugly as all get-out—crash-landed to Earth and burrowed deep under the planet's core, eventually creating the organisms that would eventually become humanity. The plan to create perfect beings which Lavos envisioned (in order to send creatures much like itself all throughout the galaxy) started to get underway during the events of Chrono Trigger, which leads Crono and the gang to travel throughout time to stop the oncoming apocalypse. All of this while Lavos is hibernating