Fairy Godmother

The Fairy Godmother is the main antagonist of Shrek 2.

Shrek 2
The Fairy Godmother wanted her son Prince Charming to marry Princess Fiona. She was enraged to discover that Fiona was married to Shrek instead, and planned to have Shrek killed. When Shrek took a Happily Ever After potion from her place, the Fairy Godmother and Prince Charming tricked everyone into thinking that Charming was Shrek. As Fiona wasn't in love with Charming (though believing him to be Shrek, saying he "lost his mind"), the Fairy Godmother instructed King Harold to give Fiona a potion that would make her fall in love with the first man she kisses, intending him to be Charming. But Harold gave her the wrong cup (on purpose), so when Charming kissed Fiona (after the fairy tale creatures fought against the Fairy Godmother and took her wand), she knocked him out afterwards, but only for a second; he took the Fairy Godmother's wand and threw it back to her. She shot a magic beam at Shrek to kill him, but King Harold jumped in front of him and his armor reflected her spell back at her, making her disappear, presumably killing her and leaving only her wand and damaged glasses behind.

Trivia:

 * She is a spoof of the real Fairy Godmother from the fairy tales.
 * In the Shrek 2 video game, the Fairy Godmother's clothes were pink instead of blue (like they were in the movie).
 * It is quite possible that she was the one that had cursed Fiona.