As seen when he narrates his story at the beginning of Shrek 2, he is self-censored. He is protrayed as a selfish and arrogant mother's boy. He is also sometimes not very intelligent, as seen where he pretends to be Shrek, he doesn't know that he needed to act like Shrek to order to deceive Fiona. He also was very offensive towards Shrek, as when he called him "dreadful". He also believed, as shown in his last moments, that the "Happily Ever After" of being with Fiona belonged to him, but that Shrek stole it from him. However, in Shrek The Third, he was eager to avenge his mother after her death in Shrek 2, caused by Harold. He, along with his mother, was remorseless, unlike Harold, who formerly conspired with them, as he had no qualms about how what they were doing would affect Shrek. He was also the only Shrek villain to never get along with Shrek, though his mother and his minor henchmen only pretended to, and the only one that Shrek never trusted. He also shares similarites with Lord Farquaad and Rumpelstiltskin, for the former, that they both wanted to marry Fiona in order to become king, for the latter, that they lives were inadventadly ruined by Shrek's rescuing of Fiona.
Not much is known about Charmings past but its known he is an mother's boy, the only one he really cares for.
Although Charming doesn't appear physically in the film, he gains a brief mention, in which Princess Fiona reveals that she thought that she would be rescued by Charming.
In Shrek 2
In Shrek 2 he is the secondary antagonist. Charming travels to the castle, where Fiona had been imprisoned prior to the first movie, only to discover that Shrek has already found her and married her, and that Big Bad Wolf (without any explanation to how Big Bad Wolf got there in the first place) has taken to sleeping in her tower.
Charming's narration in this scene (as well as his conversation with Big Bad Wolf) reveal the most important aspects of the plot from the first film.
It is later revealed that Charming is in fact the son of the Fairy Godmother, and that the Fairy Godmother wants her son to marry Fiona, so that Charming can become king (similar to Lord Farquaad's intentions from the 1st film). As such (in contrast to his Fairy Tale namesake), this version of Prince Charming plays a more villainous role.
Later, in the movie, Charming deceives Fiona into believing that he is Shrek, having been turned human by a "Happily Ever After" potion.
Nevertheless, Charming's foul attitude shines through the disguise, and Fiona realizes the truth before the end of the movie.
At the end, Charming is forced into dancing with Doris, who runs "The Poison Apple."
In Shrek The Third he returns as the main antagonist. He is stuck in the theatre, rather a stage in a bar, playing himself, due to his name.
Despite being the main character in Charming's own play (which appears to be a spoof on the classic Fairy Tale, "Rapunzel"), the audience cheers when The Shrek Mascot comes onstage.
Finally (in a version of a Buster Keaton gag), a prop tower falls on Charming, but he escapes injury, as the window passes around him.
Charming leaves the theatre, upset, and goes to his "dressing room" (in reality, the back alley, behind the bar), and starts sobbing.
There, Charming vows to his mother that he will become the king of Far Far Away.Charming organizes an army of villains in The Poison Apple, all upset that they have not gotten their "Happily Ever After."
While Shrek, Donkey, and Puss are in search of the heir to the kingdom, Fiona holds off a coup d'état by Charming.
Upon Shrek's return, he is captured by Charming.
Charming then places Shrek in the play, now being performed in an auditorium before the entire kingdom.
Shrek begins to ruin it for Charming, by making a fool of him.
As Charming is about to kill Shrek onstage, Fiona and the others burst in, getting ready to fight the villains.
Before a confrontation ensues, Artie (the true king) convinces the villains to give up their evil ways.
Charming refuses, and apparently stabs Shrek, but (as Shrek reveals to the others), he is completely unharmed; Charming (with his bad aim) merely stuck the sword between Shrek's arm and side.
Shrek throws Charming before Dragon (who tips a stone tower over Charming trapping him, and his crown rolls out).
Charming makes a cameo during the flashback montage of the end credits.
Charming appears in the story "Bates Motel", told by Puss and Donkey. He first appears as a warm and friendly motel owner, inviting the two in, but is told by Donkey to have killed the Puss. Puss then replies that Charming killed the Donkey. Puss and Donkey argue over who is killed, then resort to just making each other look bad, Puss saying that before Charming could kill him, the Puss leaped to safety. Donkey then replies that "was exactly what Charming wanted the Puss to do". Charming laughed, then pulled a lever to make Puss fall through a trapdoor. The story ends as Donkey gets Pinocchio to spray Puss with water, making him run away, which Shrek later says is cheating.