The rare Earth Kingdom rabbit-kangaroo from the world of Avatar.
In Book Two: Earth, Chapter Fifteen: The Tales of Ba Sing Se, we get a look at a kangaroo like animal during The Tale of Aang. While looking for Appa, Aang discovers a run down zoo of Earth Kingdom animals.
Aang: What kind of animal is that?
Kenji the zookeeper: Ooh, that’s a rabaroo. I wish I could get her a big open prairie like she likes… and let her hop her way to happiness.
A rabaroo is a hybrid between a rabbit and a kangaroo. It’s face and long floppy ears resembles a rabbit while the rest of the body, legs, and tail resemble a kangaroo.
Aang helps the animals and the zookeeper by earth bending a much larger, outdoor habit for the animals between the the inner and outer walls of Ba Sing Se in the Agrarian Zone.
Just like a kangaroo, a rabaroo gets around by hopping and the females of the species carry their young in a pouch. How cute!
…and apparently, much to the dismay of the cabbage merchant, they like cabbages!