Doofus Drake appears as a round chump duck 10-12-year-old child, sporting round glasses, a pink shirt with a dark blue jacket and tan pants.
Unlike the original Doofus, this version of Doofus is a fairly deranged character whose wealth has caused him to develop insane views. He has no qualms about destroying incredibly valuable objects for his own amusement, and even regards other people-including his own parents-as property that he can claim. The only individual for whom he seems to retain any respect is his late grandmother, who left him her fortune upon her death.
The money he inherited from his grandmother has turned Doofus into a terrible person with no regard for anyone else or even basic decency or consideration, as he treats his own parents as his butler and housemaid and deliberately made their lives miserable.
After his parents adopted B.O.Y.D., Doofus threw a fit that his parents showed favor and love for his newly-adoptive brother, and was absolutely furious when B.O.Y.D. claimed half of Doofus's fortune to share with his parents, which finally allowed them to regain their parental authority over Doofus and ground him indefinitely.
Doofus reappears in the reboot, but his 2017's version is radically different from his original counterpart - rather than being a benevolent friend of the McDuck children, this version is a rich, spoiled heir who turned his parents into servants, and is one of the reboot's villains.
Louie tries to befriend Doofus only to find out about Doofus' unhealthy lifestyle. Doofus was apparently not always this way according to his parents, but after the passing of his grandmother Frances (or "Gummeemama", as he refers to her), Doofus was named inheritor of her fortune and became inconsiderate, controlling, and obsessive because of it. Since he has everything his heart desires, Doofus views everyone as a possession he can treat however he wants, with the exception of his beloved grandmother, although Doofus becomes hostile when her likeness is threatened. When not exhibiting his selfishness, Doofus has a tepid, peculiar disposition and seemingly indifferent about how his quirks may startle others.
Doofus holds his Septleventh Birth-Anniversary party. It is attended by the Beagles, Flintheart Glomgold and a ventriloquist dummy, Mark Beaks and his son "BOYD", Louie and Glittering Goldie and throughout the night he ejects the guests who really aren't with families. Although he allows Glomgold to stay at first as he considered his act with his "son" soothing. Doofus does eventually kick Glomgold out after breaks the dummy. Louie and Goldie eventually expose Boyd as a robot, so Doofus kicks Beaks out of the party but keeps Boyd and orders it to kill Louie.
Goldie ends up stepping in front of B.O.Y.D. to get him to stop. To her and Louie's surprise, B.O.Y.D. shuts down and Doofus praises Louie and Goldie for passing the test. The whole ordeal was a test devised by Doofus to test their bonds of parenthood, just so Doofus could claim Goldie as his new "Goldiemama". Doofus relinquishes the gift bags to Louie and catapults him out.
Doofus encases Goldie in a glass prison and forces her to tell him stories. Louie eventually rescues Goldie and reappropriates B.O.Y.D.'s settings to treat the Drakes as his parents; the two Drakes happily embrace their new adoptive son. Feeling betrayed, Doofus throws a tantrum and threatens to sever his parents' pay, but B.O.Y.D. transfers half of Doofus' inheritance to his own bank account, which he generously shares with his new parents. Now reassured by a truly loving son, Mrs. Drake sternly informs Doofus that he is to be grounded indefinitely, for which Doofus vows revenge on Louie.
In the episode "Day of the Only Child!", where Louie tries to befriend Doofus only to find out about Doofus' unstable mind, which was brought upon from the riches left from his grandma. While Louie and Doofus are alike from their spoiled selfish natures. Louie is of a more healthy mindset and is more sensitive to others because of his family ties. Even though Llewellyn is disturbed by Doofus's antics, young Mr. Drake does enjoy the former's company at times. Until the day of his birthday where Louie ingraciated a new baby brother into the fold. To which, after B.O.Y.D ingraciates himself into the family and cuts Doofus's fortune to limit his power, he swears to get Louie for what he'd done.
Boyd is an android found by Mark Beaks, Doofus meets Boyd and they became fast friends, at first. From Boyd's positive, polite and friendly personality, but after the truth was revealed Doofus used him to hurt Louie. Louie later turned the tables and gave B.O.Y.D. to Doofus as a new younger brother whom Doofu's parents take an immediate shine too. Feeling betrayed, Doofus throws a tantrum and Mrs. Drake sternly informs Doofus that he is to be grounded indefinitely. Doofus now hates his adopted brother.
According to Frank Angones, the reason for Doofus being turned evil is because they wanted a foil to Louie on how money could ruin a person if left unchecked and because the writers are among the people disliked Doofus' characterization in the original show.
This version of Doofus is roughly modelled after Anthony Fremont, the villainous boy played by Bill Mumy at the center of The Twilight Zone episode "It's a Good Life," where the central premise was an omnipotent boy becomes a monster because no one can tell him no.