He’s a small, deer-like rabbit who could be confused with a wild cottontail if it weren’t for his rounded face and body that are more typical of Oryctolagus cuniculus, and tiny white nose tip to indicate some Dutch ancestry.
Hickory discovered the power of the snort and he uses it to express his dislike of being picked up (we only do that when absolutely necessary). It’s no coincidence that deer also snort when they are frightened. Rabbits and deer generally have much in common; it’s easy to see the resemblance when you’re interacting with Hickory, who is truly all snort and no bite. Wouldn’t you love to have a tiny deer-like rabbit in your home?