The Wickershams are monkeys in the Jungle of Nool who are Horton's tormentors, along with Vlad Vladikoff and the Sour Kangaroo.
Biography
Film
In the film, the leader is Yummo Wickersham.
Outside of Dr. Seuss series
One Whickersham from The Wubbulous World of Dr. Seuss has made strange appearances on a couple of Sesame Street media including the NasCount sketch on the "The Amazing Alphabet Race" episode in Season 38 and on the Healthy Habbits for Life video Happy Healthy Monsters.