This Daimon appeared in a flashback in the episode The Bond of Destiny! The Distant Days of Uranus. This Daimon took possession of a living boy. It attacked Haruka but was held off by Sailor Neptune. It was destroyed by Sailor Neptune, and the boy who was possessed by it survived.
Trivia[]
While this creature was never specified on screen to be a Daimon, one can assume so because of its uncanny resemblance to the Daimon in the manga and its acquirement of a human host rather than an inanimate object.
Although this Daimon had possessed a human boy, it was not humanoid in appearance. Mistress 9, another Daimon, had possessed Hotaru but appeared as a human lady rather than a monster. It's possible this Daimon was an experiment done on humans
Sailor Neptune's Deep Submerge worked differently than normal, defeating it and turning it back into a normal boy, similar to some of Sailor Moon's healing attacks. This is the only time a stock attack besides Sailor Moon's was shown the ability to heal a human.
This Daimon was not given a name. However, in the end credits it was listed as Proto-Daimon (プロトダイモーン); a term used in all book publications in Japan when referring to this monster.