This is something that needs to be seen by a vet ASAP. I don't have any clue as to what the picture is. By the location, it could be a swollen testicle that's hanging out closer to the genitalia, it could be an abscess, it could be botfly strike. If it is actively bleeding (ie bleeding doesn't stop), and/or the bunny is in pain (hunched posture, grinding teeth, lethargic, body temperature below 101F), the bunny needs to see an emergency vet. I would take her/him to the emergency vet and potentially call the police non-emergency line on the way there to explain the situation. Botfly is a fly that lays its eggs in the tissue of animals, often in the neck or near the genitals, and the larvae grow there and cause large lumps. Since the lump is the same color as her skin, it looks to be about the right size for a botfly, and you mention some holes in it, that's what I would go with right now. The fly larvae chew holes to breathe through once they get big enough. Poor hygiene is a major factor in developing these infestations, so if she was sitting in waste it's very likely. A vet will know. Find the nearest emergency vet that will see rabbits. Just call to ask if they see rabbits. I'd direct you to our listings of rabbit-savvy vets but they don't always have all the emergency vets on there.
If she is not in pain and the bleeding is stopping, it can wait until normal business hours (probably).
