Your best bud. Your bud who will do anything with you, from sitting on the couch being a potato to climbing mountains. You never get tired of being with your spudbud.
An Idaho potato doll used for marketing little potato treats known as 'spudbuddies' often served like small baked potatoes. The doll it's self was known as a "Spud Buddy". Also known as a 'spuddy buddy'. Also, Jimmy Spudbuddy (a friend or 'buddy' to potatoes ('potato' in wrestling lingo is a hard punch or hit with an object)); former referee for the all midget professional wrestling federation the Micro Wrestling Federation got this name for being a hard or "stiff" hitter in his wrestling days.
For potatoes: "Did you eat all your spudbuddy's?" "Did you bring your Spud Buddy with you?" In wrestling: "Wow he just Spudbuddy'd the hell out of him with that steel chair"