Kangaroo Monsters are a species which were seen in "The Transplant". According to the Computer: "The Kangaroo Monster is a very rare, very extinct, very huge creature. A social outgoing creature that loved to crush anything that moved to a pulpy pancake. But that was then, this is now. They're all extinct and the bones are very, very valuable." Eustace climbs on the Eiffel Tower and Courage climbs to stop Eustace, but a french police officer told them that the Eiffel Tower allows only 1 kangaroo monster, but not 2, so Courage gets off the tower and Eustace laughs at him.