Cow and Chicken - Season 2 - Eps 16: ?Which Came First
The Red Guy sneaks a crow egg under Chicken's covers while he sleeps. The next morning, Cow and Chicken find the egg, and Chicken comes to the conclusion that he is actually a girl. So, it's egg sitting for Cow and Chicken, until the egg hatches and a baby crow comes out. Now Chicken comes to the conclusion that he isn't even a chicken.
About Cow and Chicken

Title: Cow and Chicken
First Air Date: 1997-09-16
Last Air Date: 1999-08-13
Status: Ended
Rating: 7.1/10 (from 464 votes)
Language: EN
Seasons: 5
Total Episodes: 156
Network: Cartoon Network
Genres: Animation, Comedy, Kids
Production Companies: Hanna-Barbera Productions, Cartoon Network Studios, David Feiss Productions
Synopsis
Follows the surreal adventures of a cow, named Cow, and her chicken brother, named Chicken. They are often antagonized by "The Red Guy", who poses as various characters to scam them.
Cast

Charlie Adler
Cow / Chicken / The Red Guy / I.R. Baboon (voice)

Candi Milo
Mom (voice)

Dee Bradley Baker
Dad (voice)

Michael Dorn
I.M. Weasel (voice)