The ancient beast whom the Chaos Emeralds are named after, everyone's favorite amorphous blob (who isn't GE) has been making on and off apperances in the SOnic series since his debut game, Sonic Adventure. Chaos is a water-based creature who has lived for many centuries, and is said to be the originator, guardian, and God of all Chao. He has the abilities to absorb the energy of the Chaos Emeralds into himself and transform into more powerful forms, the strongest being the monsterous Perfect Chaos, capable of destroying entire civilizations. Chaos is quite a well-recieved character, being shrouded in mystery and unique in design, and just badass in general. While he did start the whole "random giant ancient monster Super Sonic has to fight" trend that has plagued basically every Sonic game since, many will agree that the original is better than the copies.