That's not a dog in a Nintendo sweater. You are looking at groomed, dyed, and trimmed dog hair. Let's call this pooch "Yoshi Dog."
Recently, the Intergroom dog grooming convention was held in New Jersey. Courtesy of Buzzfeed (via GoNintendo), here are these photos of a Nintendo themed-grooming from a creative challenge competition.
Creative? Yes. Terrifying? Definitely.
Surely, poodles are cute enough without dyeing them green and making them look like dinosaurs.