Danny Phantom is an American animated superhero television series that ran on Nickelodeon from April 3, 2004 to August 24, 2007.
A month has passed since Danny Fenton's exposure to his parents' Ghost Portal turned him into a human-ghost hybrid. When his goth friend Sam changes the lunch menu to ultra-recycle vegetarian, the vengeful ghost/meat monster of the previous Casper high school lunch lady reanimates to bring evil meat justice back to the high school. Danny must channel his newfound powers into fighting this ghost while keeping them a secret from everybody except his two best friends.
Up all night fighting the Box Ghost, Danny attracts the attention of a Ghost Hunter named Skulker, who vows to capture Danny Phantom, as he is rare and unique. The next day, Danny receives a D on his biology test, and Sam suggests that he earn extra credit by doing a report on the purple back gorilla. To help Danny manage his time, Tucker puts Danny's schedule into his PDA. In an attempt to capture Danny, Skulker sees Tucker's PDA and uses it to upgrade his armor. His power increases, but he becomes bound to Danny's schedule. Will Danny manage to evade capture by a ghostly villain and save his biology grade?
After the Box Ghost destroys Danny's locker, he's assigned a new one: Locker 724. Everyone's afraid of that locker, but Danny doesn't know why. Meanwhile, the bullies in the school are being extra mean, and Danny decides to get some "ghostly getback". It's later revealed that the former owner of his locker in the 1950s, Sidney Poindexter, was the main bully victim in his time. He punishes Danny for his actions by swapping bodies and dimensions with him, trapping Danny in a mirror world of his high school.
Already afraid that his parents might get divorced, Danny accidentally knocks Jack's wedding anniversary gift to Maddie into the Ghost Zone. Determined to get it back, Danny ventures into the Ghost Zone for the first time. Unfortunately, he is caught by a ghost warden, Walker, who makes up rules to retain order in his section of the Ghost Zone. Sentenced to 1,000 years in the Ghost Zone Prison, Danny is locked up alongside many of his ghostly enemies he has fought and sent back to the Ghost Zone. Luckily, he manages to persuade them to work with him to bust out of the prison. As the other ghosts escape, he returns to the prison cell to retrieve the gift and discovers that humans can't be hurt by ghosts in the Ghost Zone, because in the Ghost Zone, humans are the ghosts.
When he catches Danny and Dash fighting at school, Mr. Lancer offers them a chance to avoid detention by competing in a haunted house contest. When Danny feels he is losing, he steals the sword of the Fright Knight, the ghost sprint of Halloween, in an attempt to make his haunted house scarier. However, danger arises when the Fright Knight awakens and terrorizes Amity Park.
Danny and Valerie are forced to work together by watching a child-like flour sack for health class, but neither of them demonstrate willingness to help the other. After watching both Danny Phantom and the ghost hunter fighting, Skulker wonders which one is a more worthy prize. He handcuffs them together on his island and hunts them, holding the sack as ransom.
Ringmaster Freakshow arrives at Amity Park with his attraction, "Circus Gothica." His family heirloom, a ghost hypnotic, prompts Danny to join his circus and do his evil bidding. Fighting for his mind, Danny must overpower the staff's effects to save Sam's life.
Danny encounters a bratty ghost-pirate boy named Youngblood, who has teamed up with the siren-like ghost girl Ember, to kidnap all the adults in Amity Park via Ember's hypnotically enchanted music.
Vlad Plasmius places the entire town of Amity Park in jeopardy when he releases the evil Ghost King, Pariah Dark, who invades both the ghost and mortal worlds. Danny must team up with Valerie, Vlad, and several other foes to work side by side to stop the King of All Ghosts. In this episode, Danny Phantom verifies his ghost name to the people of Amity Park.
Danny is desperate to pass a standardized test called the C.A.T. After a fight with a ghost from the future sent by the mysterious Clockwork puts the answers to the C.A.T. in his hands, he decides to cheat in hopes of securing an easy pass to a great future. After fighting another ghost from the future, he, Sam and Tucker discover that Danny cheating leads to a horrible future where after the death of his family and friends, Danny grows up to be Dark Danny, the evilest and most powerful ghost on the planet who terrorizes the world. Upon discovering Clockwork's interference, Dan tries to make sure Danny's horrible future comes to pass. To save his friends, family and future, Danny must dig deep and do the right thing to ensure he becomes a better man. At the end of the episode, Sam and Tucker finds out that Jazz knows Danny’s secret and is happy with her knowing. One less person for them to worry about.
Danny is a real Grinch when it comes to the holidays, but he gets a little lesson on Christmas spirit from the Ghostwriter.
Sam signs up for a beauty pageant in order to show how "dumb and pointless" they really are. Little does she realize this is all a plot from Dora the Dragon Ghost to find a wife for her arrogant elder brother, Prince Aragon.
Danny struggles to avoid treating his friends as sidekicks, as Sam and Tucker often take the blame or beating in Danny's ghostly adventures. After leaving them to clean up a golf course, Danny meets his "cousin" Danielle ("Dani") and learns that she herself has ghost powers. As the two half-ghosts battle an enemy ghost together, Dani dodges questions from her curious relative; she feigns weakness and pretends to faint into Danny's arms after the fight. The next day, another ghost attack silences Danny's further attempts to interrogate Dani. Left to take the blame for Danny's mess once again, Sam and Tucker begin to clean the cafeteria in detention, but when they witness Dani and Vlad fly off with an unconscious Danny, they flee detention and attempt to rescue their friend. Meanwhile, Danny discovers Dani is an imperfect female clone of himself created by none other than Vlad Plasmius. Will Danny's friends abandon their hard feelings and come to his aid yet again, or will Vlad finally obtain the DNA sample he needs to clone his ideal half-ghost son?
Looking to increase his popularity as mayor of Amity Park, Vlad frees "Vortex", a weather ghost, and enslaves him to convince the people that Vlad can control the weather. But Vlad loses control of Vortex, and a battle with Danny renders the boy with weather powers of his own, controlled by his unstable emotions.
A ghost with morphing abilities named Amorpho impersonates Danny Fenton for attention, but both he and the actual Danny Phantom get locked in their forms by a Fenton Device, stuck in the cross holds of fame and madness from the citizens of Amity Park and two angry Fenton parents out for Danny Phantom himself.
A plant ghost named Undergrowth turns Amity Park into a literal jungle, in the process holding the citizens captive and even worse, kidnapping and brainwashing the nature-loving Sam into being his "daughter" and the mother to his "children". Danny must save Amity Park while also trying to keep his newly developed cryokinetic abilities in check with the help of his friend Frostbite.
Dani Phantom returns to Amity Park with a problem; she has trouble maintaining her ghost form, as she is still incomplete. Meanwhile, Vlad sends Valerie to capture Dani so that he can use her Danny Phantom-themed DNA to make a much better clone of him. A Fenton invention ends up saving Dani after she turns into ectoplasm. In the end, Valerie finds out that Vlad Masters and Vlad Plasmius are one and the same.
Danny, Sam, Tucker, and Jazz return to find some strange things emerging from the ghost portal.