Nihilego is an Ultra Beast that resembles a jellyfish. The bell is semi-translucent and encircled with several white, star-shaped markings. The wavy rim of the bell flares outward and is bright blue. Its tentacles appear gelatinous and give it a vaguely humanoid shape. Several tentacles mesh together forming the appearance of a cape or long hair, while four shorter tentacles resemble shorter hair and arms. Two long tentacles make up the legs of the human shape. In addition to its shape, it is sometimes seen acting like a young girl. According to its concept art, Nihilego's body is made of various types of glass.
Nihilego is a parasitic organism and, by latching onto one's head, is capable of injecting a neurotoxin that subtly alters the thoughts and actions of any human or Pokémon that becomes its host. This neurotoxin stimulates intense feelings of excitement while causing a loss of inhibitions, which acts to forcibly bring out any latent potential within the host while wearing away at their minds. Nihilego's exact levels of intelligence are unknown, but according to Wicke, the Aether Foundation's research suggests that it acts mainly on a self-preservation instinct.[1] In the anime, Nihilego are capable of creating illusions and seeing the memories of humans. The anime also showed that Nihilego can demonstrate emotions other than self-preservation and the ability to heal people.
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Nihilego fused with Lusamine
As shown with Lusamine, Nihilego is capable of physically merging with a host. In this "merged" state, the bell loses its stars, developing several iridescent spots across its surface. The host's body is visible within the bell with their legs dangling beneath it. Its eight tentacles become long and flattened and have numerous deep black spots with various colored diamond-shapes inside. Four of the tentacles are connected to the bell via frilly white structures; these tentacles have four spines protruding from them that can be used similarly to hands. The remaining four tentacles each terminate in a single larger spine that, in the anime, injects its toxins into the ground while sharp rocks grow below. While the anime shows that Nihilego can willingly end this merger and it may be disrupted in other ways as well, the lingering toxins and the shock of the separation can leave the host in critical condition, both physically and psychologically.
In The Homecoming Crown!, a Shiny Nihilego, nicknamed Lillie, was revealed to have rescued Mohn after he had disappeared into an Ultra Wormhole and made him see it as Lillie after he developed amnesia. Once Mohn's memory of his real family was restored, Nihilego was invited into the family and caught by Gladion.
Other
Nihilego debuted in a flashback in A Masked Warning!, where Gladion revealed to Ash that Lillie was once attacked by one when she was younger, resulting in her present fear of touching Pokémon. It reappeared in a flashback in Mission: Total Recall! and The Homecoming Crown!.
Nihilego is inspired by jellyfish, with its body made of glass to contrast the soft bodies of real jellyfish.[2] The specific species may be the Aurelia aurita or the Phyllorhiza punctata; the Ultra Beasts have been stated to be based on invasive species[3], and the Phyllorhiza punctata is an invasive species in the waters surrounding Hawaii. It may also draw inspiration from Myxozoa, a class of microscopic parasites in the phylum Cnidaria (which includes jellyfish). In particular, the Myxobolus cerebralis is known to cause the infectious "whirling disease" in various fish species. The disease causes the fish to develop bone and neurological abnormalities that cause them to swim in a corkscrew-like "whirling" motion.
Name origin
Nihilego may be a combination of nihil (Latin for indefinite nothing) and ego (Latin for I), which together roughly translates to "I am nothing" or "I have nothing". Ego may also refer to the part of the psychic apparatus that governs rational decision-making, and together with nihil reflects how the creature may have no ego, and only have an id (the survival and instinctual part of the psyche). The former may reflect its victims' lack of will outside their focus on Nihilego, while the latter may represent Nihilego's role in dominating the desires of its victims.
Uturoid may be a combination of 虚ろ utsuro (void), void, and id. It might also refer to 鬱 utsu (depression), 移ろい utsuroi (transience), and the suffix -oid (meaning "of similar form").
In other languages
Language
Title
Meaning
Japanese
ウツロイド Uturoid
From 虚ろ utsuro, void, id, and possibly the suffix -oid (meaning "of similar form")