Mythical/legendary? No.

Appears in a work of fiction? Undoubtedly in many. The principal abstract connection is also certainly referred to in works of fiction, though I know no specific examples.
Animal in question human? Yes.

As so often seems to happen, I'm finding it hard to give answers that don't mislead, so let me attempt to clarify. The words on the card have a fairly generic sense, and I am taking that as the main definition. However, the words on the card are more notable in reference to a particular abstract connection. Googling reveals that the words on the card have been used as a title for a book, a movie, and a painting, but none of these is the significant abstract connection.