Oompe is one of the Boomps, shapeshifting goblins living in Nightmare Land. The group, consisting of Oompa, Oomp, Oompe, Oompy, and Oompo, crosses paths with Nemo and his companions during their quest to rescue King Morpheus. The Boomps express a desire to aid this mission. Oompe and the others share a notable vulnerability to high-pitched sounds, especially the voice of Nemo's flying squirrel companion, Icarus. Icarus's vocalizations cause them discomfort, leading to an understanding that he should moderate his voice near them. After minions of the Nightmare King capture Nemo's allies, Oompe and the Boomps appear in Nemo's bedroom upon his awakening. They reunite with their lost member, Oompo, who delivers a crucial letter from the captured King Morpheus to Nemo. This letter contains the complete incantation needed to fully activate the royal scepter, the weapon required to defeat the Nightmare King. Oompe and the Boomps then accompany Nemo and Icarus through a portal in the sky, traveling to Nightmare Castle. They join the climactic battle against the Nightmare King, providing support during the confrontation. The description does not specify Oompe's individual actions, distinct personality traits, specific dialogue, appearance beyond being part of the group, or presence in other media adaptations or spin-offs beyond the 1989 animated film.