Season 1[]
- John Stamos as Jean Hamm
- Faith Prince as Sid's mother
- Michael Brandon as Sid's father
- Hugh Bonneville as Peter the Pillager
- "Weird Al" Yankovic as Confessional Monk
- Ricky Gervais as Xanax
- Anthony Head as Arnold Galavant
- Rutger Hauer as Kingsley
Season 2[]
- Hugh Bonneville as Peter the Pillager
- Kylie Minogue as Queen of the Enchanted Forest
- Simon Williams as Keith
- Simon Callow as Fortune teller
- Sheridan Smith as Jubilee
- Greg Wise as Arnold Galavant
- Nick Frost as Andre
- Matt Lucas as Peasant John
- Reece Shearsmith as Neo of Sporin
- Eddie Marsan as Death
- John Stamos as Jean Hamm