Denzel Quincy Crocker, a.k.a. Mr. Crocker, is a main antagonist in Fairly Odd-Parents and the Rise of Bill Arc. He is Timmy's fairy-obsessed teacher. He correctly suspects that Timmy has fairy godparents of his own, and he is often able to tell what Timmy has wished for by the smallest, most irrelevant clues. His unshakable belief in fairy godparents leads to other adults perceiving him as mentally ill.
Crocker has been shown to go to great extents to prove his theory that Timmy has fairy god parents, sinking vast quantities of money into expensive equipment and conducting elaborate experiments. He is also willing to do highly dangerous and immoral things to confirm the belief. He once put Cosmo (posing as Timmy's father) in a situation that would kill a human being, stating that "if he lives, he's a fairy." Crocker then adds, "if he dies, I have a tenure." Surprisingly, Crocker is the previous godchild of Cosmo and Wanda. Though he lost them and the memories of their time with him, his belief in fairies remains. Timmy tries to alter this event via time travel in the episode "The Secret Origin of Denzel Crocker!", but he paradoxically fails and becomes the reason Crocker lost Cosmo and Wanda and made him remember his belief in fairies. Although being a middle-aged man, he still lives with his mother, Dolores Crocker. His father has never been seen or mentioned in the series. In an ironic twist of fate, Crocker served for many decades as the main power source for all of the fairy magic; his belief is so strong that it was used to power the Big Wand, the source of all the magic in Fairy World. In one episode, this leads to the Big Wand losing all its power after he is hypnotized by his psychiatrist into believing fairies do not exist. To remedy this, Timmy, Cosmo, Wanda, Poof, and Jorgen make it so that everyone as equally crazy about fairies as Crocker is used as a source of power for the Big Wand. Due to his insanity, a running gag on the show features the "Super F", his made-up grade. Another gag has him spasm uncontrollably when he shouts, "Fairy godparents!". In "An Apologetic Vengeance", Timmy reveals that Crocker was sent to a mental institution after pinting a gun at his class in an attempt to make Timmy reveal the existence of Cosmo and Wanda.
Mr. Crocker is first seen in "Enter Timmy Turner: The Average Kid Who No One Understands", where Tord, Vinny, and Olivia visit visit him at the mental institution he was sent to 2 years prior, so they can convince him to join his evil alliance. After accepting, he joins Tord's team as they cause a Zombie apocalypse in Fairy World, follows Caillou and co. around, and helps Professor Calamitous try to flood the world. Since the Fairy World War Arc, Crocker has been helping Tord's team wreak havoc for Caillou and co.
Mr. Crocker has fair skin, blue eyes, a pair of glasses, and short black hair, as well as a hunch-back, ears on his neck, and horrible teeth. He is shown to have a generally nerdy appearance. Crocker's normal attire consists of a white long-sleeved dress shirt with a black tie, a black belt with a silver buckle, dark blue trousers, and dark blue dress shoes. His disguise during the Fairy World War Arc consists of a white flat cap with a red and gold brim, a red jacket with gold accents with a maroon and gold vest over his primary outfit, with his tie being replaced by a black bow-tie, as well as a fake mustache.