Legend has it that bunny dragons are children of the Soul of the World, and as such, contain the influences and genes of all the creatures that were possible to grow up from that world. As it is, the most obvious relatives of the BDs are dragons and, of course, rabbits.
However, that is not to say that these are the only influences. Several of the dragons have cat-like personalities and vague genetic traits. After all, a young BD's favourite past-time is often chasing yarn around. Some, however, prefer to dig holes or climb trees.
And still others have horrible, freakish abnormalities, often coming from a genetic influence of Hend coloration in their parents or grandparents, resulting in bizarre, inexplicable genetic flukes, opening an entirely new band of mutations and jumps.
Suffice to say that the genetic profile of the bunny dragons is very broad. However, there are several uniting themes. These dragons get very big, and they are very fast. They are extremely sensative creatures, very delicate despite their massive girths. Their eyes are on the sides of their heads, as befits a herbivore, though they often have massive, flesh-tearing beaks and claws, as well as a gizzard to help crush and digest bones, flesh, and exoskeletal armor.
Just what mix each dragon contains of other influences, and to what extent, however, is beyond knowing.