Cerberus

Cerberus was a child of Echidna and a Divine Beast owned by Hades. Cerberus was a three headed dog the size of an elephant who breathes poisonous breath. In Heracles' flashback his heads each have one large eye and his body appears to resemble metallic armor. Mass produced Cerberus birthed from Echidna appear within Lostbelt 5 of Fate/Grand Order. They are based on Cerberus of Proper Human History.