Agent 51 is a minor character of Bunnicula.
Agent 51 is a tall, somewhat muscular man with smooth, brown hair and he wears a spy tuxedo.
Agent 51 wanted to capture a supernatural element to keep his job, so he decided to try and capture Bunnicula. When Bunnicula saw how much Agent 51 loved his hamster, Bernie, he helped 51 keep his job without revealing his monster powers.
- Despite chasing the supernatural, he was oblivious to all the sights around Mina's apartment and only saw Bunnicula's vampire teeth.
- He is one of the few humans aware of Bunnicula's powers.