Nihilego

Nihilego (Japanese: ウツロイド Uturoid) is an Ultra Beast Pokémon introduced in Generation VII. It is a dual-type Rock/Poison Pokémon, codenamed UB-01 Symbiont. Nihilego resembles a jellyfish, with a semi-translucent bell and white star-shaped markings. Its tentacles are gelatinous, giving it a vaguely humanoid shape. Notably, Nihilego is a parasitic creature that attaches to a host's head and injects neurotoxins. This toxin enhances the host's abilities while reducing inhibitions, creating a state of excitement and a lack of self-control. It can also turn negative emotions into positive ones. Nihilego can physically merge with hosts, such as Lusamine, causing dramatic changes in both forms. The merged form features a loss of star markings and the appearance of the host within Nihilego's bell. Even after separation, the host may suffer lingering effects from Nihilego's toxins. Nihilego is known to prey on both humans and Pokémon. In the anime, it is shown that Nihilego can generate illusions and see memories.