These three Beagle Boys are different from previous incarnations as they have grayish skin, British accents and wear hooded cloaks. Their outfits are all the same, despite the fact that two of the Beagle Boys are tall and the third one is rather short. They each sport a rapier used in 17th century France.
The Beagle Boys were created in 1951 by Carl Barks as recurring villains for Scrooge McDuck in the character's comic book stories. They are a clan of criminals who frequently attempt to rob Scrooge's Money Bin, a task they fail at more often than not. In the comics they usually bore no specific names, and did not have any specific physical differences other than their arrest card placards. Though they usually work alone (only with fellow Beagles), they have been known to team-up with other criminals like Magica de Spell, Pete, or Mad Madam Mim, or hire out their services to such as Flintheart Glomgold. The Beagle Boys later appeared as regular antagonists on the animated series DuckTales, where they were given individual designs and personalities.
In Mickey, Donald, and Goofy: The Three Musketeers, these particular Beagle Boys are first seen at Princess Minnie's palace preparing to murder her by dropping a safe onto her. Their attempt fails, and they run off to tell their boss, who is revealed to be Pete, the captain of the guards. Pete is outraged by the Beagle Boys as the plan was not to murder the princess but to kidnap her only. The boys are then banished to a pit as punishment while the pit is actually adequate. Later on, by orders of Minnie, Pete assigns three janitors, Mickey, Donald and Goofy, to protect her as musketeers. Pete believing they'll do a terrible job, orders the Beagle Boys to kidnap Minnie with high hopes of success. However, upon the Beagles return, Pete realizes the three are better musketeers than he thought and advises a plan to pick them off one by one. Pete and his lieutenant Clarabelle go after Mickey and Goofy while the Beagles lure Donald into Pete's lair to be decapitated. Time restrictions force Pete's plan to take place at the grand opera where Mickey, Donald and Goofy reveal to survive their planed deaths and battle the Beagles. Pete interferes and seemingly murders Donald and Goofy along with the Beagles. Pete feels no remorse for the loss of his henchmen and continues with his plans. The Beagles are not seen or mentioned again in the film after that, but in the comic book adaptation, they are shown being arrested along with Pete.
- They are the second characters in the series to originate from a direct-to-video Disney film, the first being Experiment 221.