Mujaki is a short little dream demon dressed in red with a top hat and little black spectacles. Created an alternate reality in which Lum, Ataru and the others were all trapped inside. Has overwhelming control over manipulation of dreams into reality, but his dreams almost always turn to nightmares. His cohort is the pig-like Baku, which to my recollection is an actual mythological creature which is said to eat dreams. Mujaki is a recycled character from one of Takahashi's earlier Urusei Yatsura stories. But he's a lot more powerful and sinister in this movie than the character he was based on.
- Before the movie, he appeared in episode 21b (adapted from Chapter 31), wearing a less tasteful suit. He is also seen in the background of the ending of Episode 45.
- After the movie, he appeared in Episode 173
- He cameos in OVA 3 attending Ataru and Lum's wedding. He is seen crying and standing next to Elle. Also when Cherry takes a group photo of the wedding ceremony, he was also the on background.