bilby vs bandicoot

bilby and bandicoot both are nouns.

Word	Noun	Adjective	Verb	Adverb
bilby	Yes	No	No	No
bandicoot	Yes	No	No	No

As nouns, bandicoot is a hypernym of bilby; that is, bandicoot is a word with a broader meaning than bilby:

bilby: bandicoot with leathery ears like a rabbit
bandicoot: any of various agile ratlike terrestrial marsupials of Australia and adjacent islands; insectivorous and herbivorous

bilby (noun)	bandicoot (noun)
bandicoot with leathery ears like a rabbit	any of various agile ratlike terrestrial marsupials of Australia and adjacent islands; insectivorous and herbivorous