Your name's Percival Your name's Percival?

The term "Prison Cannon" is conjectural. The real name is unknown, and a non-canonical nickname or title is used instead. See the reasons for this title in the "Behind the scenes" section below and/or the relevant discussion on the talk page, if they exist.

Prison Cannon

A Prison Cannon was the Prison Planet's security cannon. They could launch plasma bullets, large fire balls, rockets, and even acid bombs.