Kangaroo
Kangaroos are animals found in both Australia and Yoshi's Island.
The first appearance of any kangaroos was in The Adventures of Super Mario Bros. 3 episode "7 Continents for 7 Koopas". In said episode, Cheatsy Koopa was assigned by Bowser to take over Australia. To do so, Cheatsy used his Magic Wand to turn all the human beings there into kangaroos. However, Princess Toadstool later stole Cheatsy's wand and undid his wrongdoing.
Kangaroos were later mentioned in the game Mario is Missing!, when Luigi traveled to Sydney. The plumber met a tourist there who said that he was "most interested in the Aborigines," but now wants "to see kangaroos too." The same tourist also said that, "along with 'roos and wombats," koalas are "Australian mascots."
A Kangaroo is also an ally of Yoshis from the game Yoshi's Island DS. Yoshis can ride the Kangaroo in a manner similar to how they ride Lakitu's Cloud in Super Mario World 2: Yoshi's Island; however, the Kangaroo differ greatly from the Lakitu's Clouds in that it, rather than giving Yoshi the ability to float around, give him the ability to bounce up and down at an extreme height. Yoshi can also ride the Kangaroo for an unlimited amount of time (or until the end of the area its in), unlike Lakitu's Cloud. Kangaroos are never found in the normal mass of levels; however, they are always found in Coin-filled areas sectioned away by Warp Pipes. Whenever Yoshi rides the Kangaroo, the baby riding his back seems to simply disappear, yet reappears when Yoshi stops riding the Kangaroo.