World's Cutest Dog - Boo

Sporting fan: Boo is a fan of baseball team The Cubs, left, and promoting the We Day movement, a charitable initiative of Free the Children

Shy guy: Despite Boo's popularity, his owner has chosen to stay anonymous and is only known as Jennifer

All wrapped up: Boo looks more like an exotic bear than a dog

Ladies man: Boo has celebrity fans including Reality TV star Khloe Kardashian and singer Ke$ha

Suited and booted: Boo is looking smart

Dog day out : Boo takes a trip to the Tory Burch store in New York

Snug: Boo relaxes in a cushion

Peek-a-Boo: The little fella says hello

Give us a smile: Boo wearing an Operation Smile hat and with a big fluffy head