My son wanted to be a dog, I wanted to make something else, but not a bee, so we settled on the dog.
He is a backward dalmatian, because after Halloween I'm going to pull off all the dots and then he has a black sweatsuit. A white sweatsuit on a little boy seems like a bad idea. He has a fake dalmatian, and he loves to tie the leash on the dog, then he is the "big dog" and the toy is the "little dog". Not my best work ever, but he loves the costume, and well isn't that what Halloween should be all about for a two year old.
Part of wondered why I made a dog costume, they are so average, but I couldn't find one for cheaper than I could make.