That's because tanuki
are real animals. The tanuki's zoological name is
nyctereutes pryonoides viverrinus. Although "tanuki" is sometimes translated as "raccoon dog," they are actually a basal member of the
Canidae family, making them more closely related to dogs, wolves, foxes and coyotes. Heinlad's beast mode can be configured to resemble either a biologically accurate real-life tanuki by placing him on all fours, or the mythological version of the tanuki by standing him upright and placing the saké gourd and journal in his hands.
Platypodes are real animals too.
Unicorns and jackalopes are fictitious.