Jackalope

The Jackalopes were a mythical animal in North American Folklore.

Señor 105 and Sheila encountered a species of seemingly part-rabbit part-deer Jackalopes who claimed to hail from the moon. The King Jackalope was also part-pheasant. (PROSE: Jackalope)

Luna later claimed that the Jackalopes didn't understand their own history and they were in fact failed experiments from Una Contro-Mundo where all rabbits had antlers and so did the men. (PROSE: The Gulf)

Background information
As a result of not having a license to use Mondas and the Cybermen, Cody Schell used thinly-veiled terms to refer to these concepts. Therefore the Jackalopes were supposed to be early failed experiments by the Mondasians prior to them beginning to 'upgrade' humans.