Mama Bird appears in the "Elmo the Musical" segment, "Bird the Musical."
Mama Bird leaves Elmo Bird (playing the role of her son) in charge of watching her egg while she fetches some worms at the grocery store. While she's gone, the egg is sent all over the place as Elmo Bird follows it to bring it back to the nest. When she arrives back, she discovers the egg beginning to hatch. Elmo Bird then introduced to his new baby brother.