No — dangerous
Never. Chocolate is poisonous to rabbits just as to dogs and cats — and a rabbit’s small body and inability to vomit make it even more dangerous per gram.
Theobromine and caffeine hit rabbits hard: cardiac stimulation, hyperactivity, tremors. Two factors make rabbits especially vulnerable — body size (a 2 kg rabbit reaches toxic doses with grams of dark chocolate) and the fact that rabbits physically cannot vomit, so whatever goes in must pass through. On top of the toxin, the sugar and dairy wreck cecal flora. Chocolate-coated cereals and cookies left within reach are the typical accident.
None, ever. If your rabbit ate chocolate, call an exotics/rabbit-savvy vet immediately with the chocolate type and estimated amount — activated charcoal and supportive care work best early. Do not wait for symptoms.
This article is general information, not veterinary advice. If your pet has eaten something potentially harmful or shows symptoms, contact your vet or an emergency clinic immediately. Full disclaimer.