Sonic & The Olympus Heroes - Concept art: Bad guys (Patreon)

Designed by Baban and myselfHello there!

Here are the references we used for Ceto (previously called Echidna) and the Hydra. Ceto is essentially Echidna, with the same backstory as Typhon's wife and the mother of monsters (including the Hydra). Because of Knuckles the Echidna, I decided to change her name to that of a primordial sea goddess, who is potentially Echidna's mother.

As for the Hydra, since Sonic doesn’t (often) kill, I decided the mythological monsters would be "machines." They’re more like magical creatures made of stone and energy. You might have noticed that in the pilot, the Hydra only had one head. Well, if you've read it, you can easily guess what’s coming next, haha.

Hence the Heracles chapter, where the Hydra appears with multiple heads.

Classic Hydra.