Nihilego is an Ultra Beast which resembles a jellyfish. It is mostly white and has tentacles shaped like the hair, dress, and legs of a girl. On top of its head is an object that looks like a sun hat. This "hat" has six pointed stars around the crown, and the brim has a blue edge. The ends of the "hair" fly out, resembling arms, and the outer tentacles of the "dress" have two bubbles inside.
Nihilego is somewhat of a parasite, but once it has a host, instead of controlling it, it injects a neurotoxin that manipulates the thoughts and actions of the host. This neurotoxin stimulates intense feelings of excitement and lack of inhibition in the host, and boosts the host's skills to a great extent.
- No other Pokémon has the same type combination as Nihilego. It is the only Ultra Beast to have a unique type combination.
- Nihilego is the only genderless Poison-type Pokémon.
- Nihilego also seems to take on a likeness to one of the main characters "Lillie" due to its striking resemblance to her silhouette.
Origin
Nihilego may be inspired by a jellyfish, especially Aurelia aurita. It may also draw inspiration from Myxozoa, a class of microscopic Cnidarian parasites, particularly the Myxobolus cerebralis that are known to infect "whirling disease" in various fish species. The disease causes the fish to become crazed and lose control of its behavior.
Name origin
Nihilego may be a combination of nihil (Latin for indefinite nothing) and ego.
Utsuroido may be a combination of 虚ろ utsuro (void), void, and id.