A mythical critter (Jackalopus lunaticus) which resembles a large jackrabbit with antelope antlers. They are native to Texas, but have been encountered in other states in small concentrations.
Males of the species appear to suffer from heightened aggressiveness during the mating season, which is eleven months long. The females are somewhat more sensible, though not by much. Both have a tendency to charge much larger animals (and people and automobiles and houses) that they feel are trespassing in their territory. Luckily, most animals feel sorry for a varmint that's so crackers, so they just try to stay out of their way. However, a growing number of jackalopes die under the wheels of semis that had the nerve to look at some jackalope's woman the wrong way.
Luckily, the jackalope has no natural enemies. They're composed almost entirely of bones and gristle, and they taste disturbingly like uncooked asparagus. It's said that a coyote will eat anything, but that's only true because a coyote will eat anything to avoid having to eat a jackalope.
I know you've probably seen postcards with pictures of jackalopes on them. They're all fakes. No kidding. A real jackalope's ears are longer, and its fur is dirtier and more matted. But the biggest difference is the eyes. Nothing bunny-like in those eyes. Crazed, murderous, near-genocidal rage. A jackalope makes Kathie Lee Gifford look calm and mild-mannered.