Ritterrüstung von Heulsuse

This section may contain major spoilers for the Kazumi Magica manga!

Please refrain from reading if you haven't read the latest chapter yet.

Ritterrüstung von Heulsuse (Knight equipment of crybaby) is a witch in Puella Magi Kazumi Magica. She is the witch form of Satomi Usagi appearing in Kazumi Magica Chapter 15. It is vaguely humanoid, with a whistle for a head and a circular cage for a dress. The witch has a smaller, rabbit-like form that hides inside of the outer shell's dress. Kazumi uses 'La Bestia' to turn the witches familiars against her and destroy the witch's outer shell. Once her true form is shown, Kazumi grabs the rabbit and slams it against the wall, killing it. Though it then transforms back to a dead and bloody Satomi making Kazumi realise she's killed her friend.

Ritterrüstung von Heulsuse

Ritterrüstung von Heulsuse
Runes	RITTERRÜSTUNG VON HEULSUSE
Type	Unknown
Nature	Cowardice
Episodes	Kazumi Magica Chapter 15: Essence of Satomi

The outer shell is a beastmaster, but the main body is a timid rabbit.

Minions

Unknown
Runes	?????
Type	Unknown witch's minion
Duty	Unknown
Episodes	Kazumi Magica Chapter 15: Essence of Satomi

Trivia

The witch appears to be an animal tamer. Her barrier is decorated with cages and she uses a whip to attack..
The name means: 'knight equipment of crybaby', with the 'knight equipment' reflecting the outer shell, and the 'crybaby' reflecting the inner body of the witch. The word 'Ritterstüng' is wrongly spelled here; the correct form would be 'Ritter Ausrüstung'.
The rabbit-like form may be the witch's true form.
Her familiars are small cats with mouths on their foreheads. They are somewhat reminiscent of Juubey and Satomi's childhood pet Sare. Kazumi turns them against the witch with Mirai Wakaba's 'La Bestia' and uses them to blow up its outer shell.