Suleika

Suleika is a witch villain appearing in Puella Magi Madoka Magica. She doesn't appear in any anime episodes but she appears in the fangame Magical Crusaders Matagi Magica. Her familiar Ulla was swiftly defeated by Mami at the beginning of Episode 3, which was made infamous for the appearance of Charlotte as well as Mami's early death by Charlotte's hands.

Suleika is the dark witch (has not debuted), with a delusional nature. Her power grows as the darkness deepens. In total darkness she can scarcely be matched. She's almost unrivaled inside an absolute black; however, with lights as numerous as they are nowadays, she is not a witch to be feared.

Trivia

 * Sketches from the Production Note show her as a star with several arms.
 * Suleika is a German form of the name Zuleika of arabian origin that means fair; brilliant and lovely. It was made popular in Germany by the poem collection West-östlicher Divan by Johann Wolfgang von Goethe.
 * Ulla is a nordic name that means will, determination. In German-speaking countries, Ulla is a variant of the name Ursula of Latin origin that means little she-bear.

Speculation
Before it was disproven, it was speculated that Suleika was the Witch from the dream in episode one. It is now known that that witch is Walpurgis.