On Yuri's Night, the Callistos are tasked with bringing alien musician Bootjet Groovestar to the Tethoscape.
- Cullen McCarthy as Miles Callisto
- Fiona Bishop as Loretta Callisto
- Olivia Munn as Phoebe Callisto
- Tom Kenny as Leo Callisto/Dethalian Guard/Announcer/Crowd
- Dee Bradley Baker as M.E.R.C./Adorbix
- Danny Jacob as Admiral Watson
- Diedrich Bader as Admiral Crick/Dethalian Guard/Dethalian Commander
- Grey DeLisle as Stella/Crowd
- Kevin Michael Richardson as Bootjet Groovestar
- Yuri's Night refers to April 12, the anniversery of Vostok 1, on which Soviet cosmonaut Yuri Gagarin became the first human in space on that day in 1961. It was also the day the first American space shuttle (Columbia) was launched in 1981.