Sour Kangaroo a.k.a Jane Kangaroo is a busybody and creator of the jungle's laws who is skeptical about the existence of the Whos and Whoville on a dust speck.
- In the 1970 TV special, her name was Jane, and she was yellow. In Jim Henson's The Wubbulous World of Dr. Seuss, her name was also Jane, and she was orange. In the 2008 Fox/Blue Sky film, she had no particular name, and she was purple.
- She was voiced by June Foray in the TV special, Stephanie D'Abruzzo in Jim Henson's The Wubbulous World of Dr. Seuss, and Carol Burnett in the 2008 film.
- In one episode of Wubbulous World, her father, Jacob, who's hard of hearing, appears.
- In Seussical, her joey is portrayed as a puppet.