CERBERUS

Cer″be‐rus (?), n. [] 1. 1. (Class. Myth.) A monster, in the shape of a three-headed dog, guarding the entrance into the infernal regions, Hence: Any vigilant custodian or guardian, esp. if surly.
2. 2. (Zoöl.) A genus of East Indian serpents, allied to the pythons; the bokadam.