Nightmares are new type of monster introduced in Rebellion. They resemble dolls with a pair of disembodied blue hands, and primarily attack by shooting exploding objects.
It is later revealed in the movie that the nightmares are actually false opponents created by the witch barrier Rebellion takes place in.
At the moment, Nightmares exclusively appear in Rebellion.
Two nightmares appear in the movie. The first appears at the very beginning and is initially attacked by Madoka Kaname, Sayaka Miki, and Kyoko Sakura. The nightmare is driven into a dining room where Mami Tomoe and Bebe are waiting. The magical girls then appear to defeat the nightmare by feeding food to it. It's later revealed that Homura Akemi had assisted the magical girls in secret.
The second nightmare is born from Hitomi Shizuki, when she feels frustration over her relationship with Kyosuke Kamijo. Hitomi is seemingly swallowed up by her bed as the nightmare appears. The magical girls contain the nightmare and then defeat it by singing the Cake Song. At the end of the song, the nightmare turns into a cake which Bebe swallows whole. Bebe then spits out a blob resembling Hitomi's head and a paper with a picture of a violin on it. Sayaka catches both things, and then throws the paper into the air. The paper turns into a silhouette of Kyosuke playing the violin. The blob flies up after the silhouette and vanishes into sparkles that purify the magical girls' soul gems. Hitomi then reappears in her bedroom.
It is eventually revealed that the characters are actually in Homura's witch barrier. The nightmares were created by the Homura's subconscious so the magical girls would have enemies to fight.
- The disembodied hands of the nightmares hint at the fact that they're puppets created by a witch. Furthermore, one of the hands has a covering over it's middle finger, which is the same finger a magical girl wears her ring on.
- Note how the dots on the hands resemble the ones that appear on Homura when she starts to discover she might be a witch.
- A mare or nightmare (Proto-Germanic: *marōn; Old English: mære; Old Norse: mara; German: Nachtmahr) is an evil spirit or goblin in Germanic folklore which rides on people's chests while they sleep, bringing on bad dreams (or "nightmares"). The mare is often similar to the mythical creatures succubus and incubus, and was likely inspired by sleep paralysis.
- It is interesting to note that mara, besides being a root-word for nightmare, is also the name of a Buddhist deity analogous to the devil. Although this may be a coincidence, Homura does ascend to become a Mara-like figure at the end of Rebellion.