A cute baby bulldog. Usually a black french bulldog puppy, sporting oversized ears and large round eyes. Also looks like a furry fruitbat that can't fly, or a mix between a kitten, puppy and a rabbit. Boomies often hop around and hump other dogs.
Q: "What the heck was THAT? It looked like a fruit bat just ran across the street."
A: "Oh that was just a boomie..."