Duck Avenger is the superhero alter-ego of Donald Duck, Disney's most famous duck. He protects the city of Duckburg from common criminals and worldwide threats to duckkind.
When the abandoned Villa Rose is left to Donald Duck, he happens upon the diary of its former owner, John Quackett, who was a famous gentleman thief and vigilante known as Fantomallard. Wanting to seek revenge over his two biggest grievances, Gladstone Gander and uncle Scrooge, he takes up Quackett's old costume and, with some gadgets from Gyro Gearloose, becomes the Diabolical Duck Avenger.
Duck Avenger later turns away from self-vindication and begins crimefighting, becoming a celebrated hero in Duckburg.
After genius Everett Ducklair skips town for a Tibetan monastery, most of his assets are bought by Scrooge, including the 150-floor Ducklair Tower. Donald is made its custodian, and he discovers that the tower actually has 151 floors. He investigates later that night as the Duck Avenger, and is swallowed by a gargoyle on the roof. He finds himself in the secret floor and comes face to face with the tower's AI, a mighty computer named One. He offers to be Duck Avenger's partner, which includes access to Ducklair's technology, including the versatile X-Transformer shield. Thus, the 151st floor becomes his new hideout, and the two work together to battle all-new villains, including hostile aliens, and time-traveling bandits.
With or without the mask, this is core Donald Duck. He is snarky, jovial, and has the temper of a raging volcano. When under his Duck Avenger persona, his cowardice is exchanged for courage, boisterous confidence, and a strong drive for justice. He knows what's right and will fight to the bitter end. He is strongly devoted to his family and no matter how much they aggravate or frustrate him, he will always be there for them, especially for his twin sister Della, her kids Huey, Dewey, and Louie. and (albeit reluctantly sometimes) his rich uncle Scrooge.
During his first solo visit to St. Canard, he happened upon Negaduck, who was quick to strap him to a giant pizza oven. Quiverwing stepped in to save the day, and he may have put Negaduck in a particularly uncomfortable situation. (cough)
Duck Avenger met Darkwing on a SHUSH assignment in which Professor Moliarty besieged the west coast with earthquakes. The job had its ups and downs but the two heroes came together and saved the day, which begun their friendly rivalry.
The first time Feliciana fought at Duck Avenger's side was when she was a kid, going to school in Duckburg as part of a foreign exchange student program. Evronians invaded Ducklair Tower on a field trip and D.A. allowed her to help out.
On a case in St. Canard, Duck Avenger met the evil demon Malicia Macawber for the first time. After battling her briefly, he went to ask her cousin, Morgana, for help, and she recruited Darkwing. Together they put a stop to her sinister plan.
Darkwing and Duck Avenger maintain a friendly rivalry as superheroes. Duck Avenger plays the more practical, no-nonsense hero to Darkwing's more theatrical antics, though he can get dramatic as well.
Friends with Quiverwing after a nasty encounter with Negaduck. He considers him a trusted ally, and generally gets along with him better than Darkwing.
The first villain he encountered in St. Canard. Duck Avenger will face him if needed, though his tactics and brutality scare him, so he prefers to keep a big distance.
When Feliciana is adopted by Jose Carioca and Panchito Pistoles, they choose their third Caballero, Donald, to be her godfather. He loves Feli as if he were his own child, like Huey, Dewey, and Louie. She sometimes plays sidekick to Duck Avenger, though this is a dormant arrangement since she grew up and became a S.H.U.S.H. agent.