Mahou Shoujo Madoka Magica character.
The witch that Tomoe Mami battles and lost in episode 3, and has two forms; the first is a limp stuffed doll-like creature wearing a cape, the second is a massive black worm with multicolored eyes.
Charlotte is a dessert witch who is capable of creating infinite amounts of any dessert she desires, but is unable to make the cheese that she loves most. One could easily catch her off-guard with a piece of cheese. She is also very tenacious, and never gives up. Charlotte's minions are Pyotr.
It is confirmed that Momoe Nagisa, a character introduced in the third movie, is Charlotte's human form.