The term WOMBAT RELATIVE is solved by the crossword answer KOALA, which is a five-letter word. Koalas are marsupials native to Australia and are closely related to wombats. They are both members of the family Phascolarctidae, which is part of the order Diprotodontia. Koalas are known for their large, round ears and their grey fur. They feed mainly on eucalyptus leaves and spend most of their time in trees.