Burpin' Babies / Backpack Payback

S1, E18: Burpin' Babies / Backpack Payback

Available on Prime Video
Burpin' Babies: Kent's youth serum works a little too well and turns the gang into screaming babies. The serum soon wears off - sort of - now they're adults trapped in baby bodies and Von Bolt doesn't know whether to obey or burp them.