Lassoo

Affiliations: Baroque Works(former); New Spiders Cafe Devil Fruit: Inu Inu no Mi, Model: Dachshund (Mutt-Mutt Fruit) Devil Fruit Type: Zoan Lassoo is Mr. 4's gun that consumed a Devil Fruit through some unknown method which allows it to become a living dog. He is a sandy-brown gun, similar to a bazooka, that has handles on the sides and a contoured barrel. Lassoo is always suffering from some kind of cold that makes him have a running nose and sneeze (which makes him fire cannonballs). He seems to be very loyal to his master, as he did everything he said without question.

(Source: One Piece Wiki)