Man insists he is a dog, responds to "Boomer"

It sounds like Gary Matthews, 48, has lots of fun wandering Pittsburgh, barking at cars and digging holes.

"I don't eat dog food every day," Matthews told ABCNews.com "It's a special thing for me to do once in awhile to get closer to feeling like a canine. I eat the canned kind. It's not bad — it tastes OK. I eat regular human food, too, like pizza."