Frollo is a member of the Villain League and the main antagonist in Spongebob meets the Hunchback of Notre Dame
Frollo is the stern, predjudiced judge of Paris, using his power to carry out his personal vendettas. He believes that everything he does is in the name of God, even as he attacks the cathedral of Notre Dame. He comes to lust for the beautiful Esmerelda, but even blames his own lust for her on witchcraft and the devil rather than accept that he himself is committing crimes and sins. His lust drives him insane.
The Hunchback of Notre Dame
At the film's beginning, Frollo ambushes a group of gypsies entering Paris illegally and chases one of them to Notre Dame where he kills her. However, he discovers that the gypsy's "stolen good" was actually her deformed baby son, whom he prepares to kill but for the intervention of the Archdeacon, who reprimands Frollo for killing an innocent woman and tells him that the only way to make up for his sin is to raise the boy as his own son, to which he begrudgingly agrees. Frollo names the boy "Quasimodo" (literally "Near-perfect mode" or "Half-formed"), and raises him in the Cathedral, hidden from the outside world, constantly teaching him that he would be considered an ugly and hideous monster by the cruel outside world.
20 years later, Frollo summons Captain Phoebus to aid him in his war with the gypsies, and at the same time, Quasimodo begins to rebel Frollo's strict actions. He attends the Feast of Fools, where he becomes enamoured of Esmeralda, a gypsy performing at the festival, but when Quasimodo is crowned King of Fools and then humiliated by the crowd, Frollo refuses to help him in order to teach him a lesson. Esmeralda openly defies Frollo for his cruelty, and in retaliation, Frollo orders her arrested. She escapes into the Cathedral, where he corners her and tells her that he will arrest her if she dares to leave. However, Quasimodo helps her escape. Frollo gets wind of this and orders a city-wide manhunt for Esmeralda, at the same time hunted by the lust he feels for her.
As Frollo nears insanity, Phoebus defies him and is ordered killed, although Esmeralda rescues him. Frollo eventually tricks Quasimodo into leading him to the gypsy hideout, the Court of Miracles, and plans to have Esmeralda executed the next day. Frollo succumbs to his desires and offers Esmeralda one last chance to live as his mistress, but she refuses and he orders her executed. Seeing Esmeralda suffering finally snaps Quasimodo and he openly defies Frollo, rescuing Esmeralda and pouring molten copper onto the streets of Paris, keeping anyone from entering the Cathedral. Frollo manages to enter and finds Quasimodo crying over Esmeralda's unconscious body. Frollo attempts to stab Quasimodo from behind, but Quasimodo retaliates and nearly kills Frollo in his rage. As Frollo goes for Esmeralda, Quasimodo takes her to the balconies and fights Frollo. During the fight, Frollo reveals to Quasimodo that he killed his mother, and eventually, the two fall from the Cathedral balcony. While Quasimodo is caught in mid-air by Phoebus, Frollo falls to his death in the molten copper below, ironically after stating that God will smite the wicked and hurl them down the fiery pit.
Difference from the original
Frollo was very different in the original novel. He was far more compassionate, caring, and tragic, as well as signifacantly less villianous in the original novel. As the archdeacon of Notre Dame in the original novel, he took Quasimodo in willingly as his own son when his mother abandoned him in the book (yes, Quasimodo's mother abandoned him instead of Frollo just killing her himself) and named him after Quasimodo Sunday, instead of his disfigurement. He even helped Quasimodo develop some sort of sign language after the latter became deaf from becoming the bellringer. He only becomes the villain when Esmerelda enters the picture. His lust drives him insane much like in the disney version and the rest is history. The only difference at this point was that Frollo actually succeeded at killing Esmeralda just before Quasimodo throws him off of Notre Dame, killing him.
Role in the Series
Frollo, after his death, was resurrected by the Villain League, and forced to serve as one of the team's reinforcement members. Frollo was at first fearful of this "Freeing the darkspawn" stuff and even believed the darkspawn has associations with the devil, (although darkspawn, as evil as they are, share no such thing, since their master, Chernabog, is sealed away right now, but are demonic in their own right), but Mirage eventually convinced him about having the darkspawn control Esmerelda into falling in love with Frollo, and with such, Frollo accepted his newfound villain leage life. In The Black Cauldron, Frollo didn't play much of a role aside from sing Hellfire strangely about Spongebob being converted into evil, more plot holes aside, and appearing as one of the new villains for a brief cameo and only appearing in text dialogue, due to Scroopfan's weakness to get distracted with too much villains to work with, as he at least only wanted a fewer number of villains, or at least the villains he wanted to include (which he can't remember now). Frollo is also set to be the main villain of Spyro meets the Hunchback of Notre Dame. In it, it will be revealed that Frollo plummeted towards the darkness due to the guidance of Maleficent and Chernabog manipulating him during the Hellfire sequence.
However, what Frollo doesn't realize is that when he went insane in the final battle of Notre Dame, his heart was consumed by darkness, turning him into a Heartless while also creating a Nobody from his strong will to survive. When Maleficent resurrected him from the darkness, she revived only the Heartless part of his soul, but used glamor magic to make Frollo's Heartless appear to look like his former human self. When Frollo appeared in the Black Cauldron, he still didn't realize that he was actually a Heartless. However, that may change in Spirited Away when Frollo's Nobody debuts and Maleficent's glamor magic wears off on Frollo, finally revealing him to be the Heartless he truly was. How Frollo will react to this has yet to be determined.