Morton the Elephant Bird

From Muppet Wiki

Morton the Elephant Bird was the son of Horton the Elephant on The Wubbulous World of Dr. Seuss. The character appeared briefly, without a name, in the Dr. Seuss book Horton Hatches the Egg. Morton loves and adores his pop, and Thidwick the Big-Hearted Moose serves as an honorary uncle to him. Morton's best friend is usually Junior Kangaroo.