- Seth MacFarlane (Peter Griffin / Brian Griffin / Stewie Griffin / Glenn Quagmire (voice))
- Alex Borstein (Lois Griffin / Tricia Takanawa / Loretta Brown / Barbara Pewterschmidt (voice))
- Mila Kunis (Meg Griffin (voice))
- Seth Green (Chris Griffin (voice))
- Patrick Warburton (Joe Swanson (voice))
- Arif Zahir (Cleveland Brown (voice))
Family Guy — S18E15
Episode: Baby Stewie
Air Date: 2020-03-15
Runtime: 22 min
Overview
Stewie builds a DNA-altering machine that will allow him to remain smart forever, but the invention has the adverse effect and he instead transforms into what he should have always been - an actual baby.