Pete
The bunkin has either an abscess with massive amounts of scar tissue, or a tumor - the former being strange because it appeared so quickly, the second being rare in bunnies as it appears relatively skin-based. If it is a tumor, it's also grown quickly, which may have led to the center necrotizing. As it is, he went to the vet this afternoon (as I only saw it this morning) and had a drain put in; he's now on baytrill with a side order of pinapple juice; I'm going to be syringing baby food into him tomorrow, which he'll love. Almost as much as he loves his buster collar.