- Peridot (Steven Universe) as Basil of Baker Street
- Steven (Steven Universe) as Doctor Dawson
- Wendy Testaburger (South Park) as Olivia Flaversham
- Jasper (Steven Universe) as Professor Ratigan
- Zuko (Avatar: The Last Airbender) as Fidget
- Harley Quinn (Batman: The Animated Series) as Felicia
- Appa (Avatar: The Last Airbender) as Toby
- Greg Universe (Steven Universe) as Hiram Flaversham
- Moon Butterfly (Star VS the Forces of Evil) as Queen Mousetoria
- Raven (Teen Titans) as Miss Kitty Mouse
- the South Park boys as stripclub attendants
- Bessy Busybody (LazyTown) as Basil's butler
- Homeworld Gems (Steven Universe) as Ratigan's supporters
- Leggy Ruby (Steven Universe) as Bartholomew
- Basil, Dawson, Ratigan and Bartholomew are genderswapped.
- This takes place in Empire City, which is like a mashup of huge cities in the Steven Universe world.