Up until now this feature has been trapped in the Golden Age of Comics; let's jump ahead!
Trapped in a world he never made, Howard the Duck was an acerbic, cantankerous waterfowl who kept getting into trouble alongside his (human) female companion Beverly Switzler.
Trapped in a world he never made, Leonard the Duck was an acerbic, cantankerous waterfowl who kept getting into trouble alongside his (human) female companion Rhonda Martini.
The Story Behind the Story: Howard the Duck entered the pages of Steve Gerber's Man-Thing as a mere flight of fancy from artist Frank Brunner, but Gerber became so taken with the character's possibilities that he kept bringing him back until he finally landed his own series, later his own newspaper strip and even a presidential campaign! Howard was one of the most popular comic book characters of his time, but his success came almost entirely from Gerber. When Gerber attempted to assert his ownership of Howard, publisher Marvel Comics disagreed and Gerber exited; without Gerber and facing restrictions from Disney (who objected to Howard's resemblance to Donald), the character became mostly unusable (and particularly toxic after his terrible feature film became a particularly memorable flop).
Gerber went on to write similar characters (such as Stewart the Rat and Destroyer Duck) who failed to catch on, but occasionally returned to Howard. In the late 90s, Marvel became interested in Howard again and lured Gerber back for a Spider-Man/Howard the Duck team-up in Spider-Man Team-Up #5. However, Gerber took the opportunity to set up a cross-company crossover with Image's Savage Dragon/Destroyer Duck comic, which Gerber was also writing. Marvel had no idea what was happening in the Image pages, but it turned out Gerber had planned a heist far more interesting than the tale itself: in the Image book, Howard was cloned several times and it was a Howard clone who wound up returning to the Marvel Universe with Spider-Man; the real Howard changed his name to Leonard and changed his feathers' colors. Thus, Gerber had tricked Marvel out of their own property! You can imagine how thrilled the company was with Gerber after this. Having gone to this much trouble to regain control over Howard, it shouldn't surprise you to learn Gerber did almost nothing with Leonard afterward. Strangely, Gerber eventually came back to Marvel for another Howard comic, meaning by his own rules he was writing about Howard's clone.
Fortunately, there's a happy ending to this tale: now that Disney owns Marvel they can dictate terms on all of Marvel's creations instead of singling out Howard. And now that Gerber is deceased writers can use Howard again without feeling guilty! Everyone wins! ...Except for Leonard, the one true Howard, who remains forgotten.