Mad Dog is one of two main henchmen Air Pirates of Don Karnage. Even though he is not Karnage's second in command or first mate, Karnage sees him, Dumptruck, and Gliber as his tree most loyal pirates (that is half true).
Karnmage usually assigns Mad Dog and Dump Truck doing dirty jobs for him. On one occasion in first episodes, Karnage discuss Mad Dog and DumpTruck to pose as a couple, so they can sneak into Cape Suzette and kidnap Rebecca Cuningham and her daughter Molly, so they can blackmail Baloo and Kit Cloudkicker to give them back crystal they need for their lightning gun.
Karnage usually treats Mad Dog and the rest of the pirates without respect, smacking them when they do something wrong, but he also, in few occasions, wanted them to be happy, as in episode called Molly Christmas.
In one episode, when Karnage captured Baloo, Kit, who was escaping to help Baloo and other captives, tricked Mad Dog by dressing into some clothes and playing as Mad Dog is looking at his mirror.
On other occasion in Polly wants a treasure, when Karnage captured Kit, Mad Dog and Dumptruck started fighting with Ignaz the Parrot. When the bird got away, Karnage ordered his men to tie Kit for a tree, and Mad Dog tickled Kit's feet with one of Ignaz feathers pulled out from a fight, not feeling sorry of Kit who laughed hysterically and begged him to stop...When Baloo showed up, Karnage ordered two of his minions to fight him and parrot, and both of them run across Karnage.
In episode with Cliff guns being take on over by Pirates, Mad Dog, Dump Truck and Max other Air Pirate played bowling with cannon ammunition, and two times fought off Baloo and Louie.
Even if he is the brain of his and Dumptruck duo, he is not much brighter than his partner. He is ruthless, but also a coward, being worried when he and Dump Truck ran on to Kit in Cape Suzette, where they tried to kidnap a rich boy.
Also he is something of feminized, not wanting to help Dumptruck put water mines, because he needed to manicure his nails, and he was discussed by Baloo and Karnage being obviously stuck by glue together, telling they are some kind of a monster.