Cerberus are a pseudohuman species of beings that appear prominently in Greek Mythology.

Said to be the guardians of the Greek underworld known as Hades, the Cerberus are noted for having three heads, each with their own conscious personalities, and a snake as their tail. In Greek literature, the hero Heracles was tasked with retrieving a Cerberus from Hades as the final of his 12 labours. Ruberu's two heads are called Ke and Su. All 3 of them together would be Ke, Rubero, Su (Keruberos aka the