Mulaney and Samberg donned matching Jimmy Kimmel Live-themed hats, shirts, jackets and sweat pants with fanny packs and discussed their upcoming Disney+ feature, Chip 'n Dale: Rescue Rangers.
"We were really expecting to just be guests like a few hours ago, but here we are making actual television that is going to air on television," Samberg said after introducing Mulaney.
"This is the only thing on ABC right now. There's nothing else," Mulaney added before the pair started laughing.
Mulaney and Samberg each took turns as host to interview the other and presented the same clip from Chip 'n Dale: Rescue Rangers featuring the titular characters escaping from pursuers by flushing themselves down a toilet.
The action-comedy film, which uses a mix of live-action and CG animated graphics, is coming to Disney+ on Friday.
Mulaney also talked about his five-month-old son Malcolm, who he shares with Olivia Munn. Mulaney said they started feeding his son peanut butter that he had received from Kimmel and presented a photo of himself feeding the infant.
"That's him pushing away the spoon when he found out that the man who gave us the peanut butter is riddled with COVID," Mulaney said.