As an actor, Starling prided himself on his abilities as a stuntman, despite the injuries he often sustained while performing. He was so dedicated to his role that he would break character and insist that the filming continue. However, in his later years, Starling seems to have nothing to his credit other than his role as Darkwing, whether because he couldn't or wouldn't find other work. Moreover, Starling seemed to have little to no regard for his fans, regarding them only as a source of income. He was initially thrilled at the prospect of Dewey Duck as a new fan but quickly soured upon recognizing Launchpad, failing to appreciate the awe in which the pilot held him.
Unlike Dewey and Launchpad, Starling was entirely content with Alistair Boorswan's take on Darkwing, "Darkwing: First Darkness", while he believed he would be reprising the role. However, his rage at being replaced led him to physically assault Drake Mallard, and he soon took advantage of Launchpad's hero worship to coerce him into helping him break back onto the studio lot. Starling's ego sent him into a maniacal spiral in which he assaulted and imprisoned Mallard and several guards before hijacking an electric cannon and wreaking havoc on the film set. He later showed a willingness to inflict fatal injury on Drake Mallard when the latter appeared in costume, and irritation when Launchpad attempted to stop their fighting.
For a brief instant, the words of Mallard and Launchpad moved Starling to reflect on how far he had departed from his heroic television role. However, when Launchpad was threatened and Mallard went to his aid, Starling saw it as upstaging and intervened. Having been caught in the explosion of a large electrode, Starling was believed to have been killed. With the movie cancelled, Launchpad convinces Mallard to become Darkwing in real life to honor their fallen idol. But in actuality, Jim Starling had fallen into a drain and survived. As he walked through a pipe, a purple liquid leached from his Darkwing outfit, changing its color to red and yellow, and now looking exactly like Negaduck. He believed that Mallard had intended not merely to replace him but to kill him and steal his place as Darkwing, using Starling's biggest fan as bait. With this twisted misconception and a furiously wounded ego, Starling seeks revenge against Drake Mallard.
Enhanced Durability: Starling has shown to be more durable than a normal person able to take several blows and stay standing, and also managing to survive an explosion which would have killed an ordinary person.
Skilled hand-to-hand combatant: As expected due to being a to playing Darkwing Duck for years, Jim has trained extensively on his own in hand to hand combat.
Master martial artist: Jim has excellent martial art skills, nearly being on par with that of former secret agent Mrs. Beakley, and equal of that to Drake Mallard.
Lightning Cannon: Starling temporarily had access to a large cannon which fired bolts of electricity in the direction in which it was aimed, if aimed at flammable materials it causes them to catch fire.
Drake is Jim Starling's successor set to appear in the movie based on the Darkwing Duck tv show. Drake idolized Darkwing Duck so much as a child that he stood up to a bully at a younger age. Starling is contemptuous towards his successor and wants to portray Darkwing Duck in the movie himself out of a sense of entitlement. It is not long before a brawl breaks out on the set between Drake and Jim over who is the best Darkwing Duck.
His name is a reference to Jim Cummings, Darkwing and Negaduck's voice actor.
In the original Darkwing Duck series Negaduck was Darkwing Duck from an alternate dimension where he chose to be a villain rather than a hero, at least according to one origin story. So this incarnation being a Darkwing Duck that turned evil is rather fitting.
Another origin story depicted him as Darkwing's evil cousin from another planet, but the episode in which this took place was clearly intended to parody various comic book and television stories rather than to be taken seriously.
Jim Starling's tragic fall from grace seems to be based on Basil Karlo, who would eventually become one of Batman's enemies, Clayface.