Cerberus /(?)/

Cer·be·rus

Cerberus

n.
  1. 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. (Class. Myth.)
  2. A genus of East Indian serpents, allied to the pythons; the bokadam. (Zool.)