The Daimons are created from various objects. Daimon pods are implanted in an item. When a victim makes contact with the item, the item is transformed into a Daimon, who proceeds to steal the victim's Pure Heart.
When a Daimon is killed, the item reverts to its original form, the now-useless Daimon pod exits the item and breaks in two, and a little black spirit emerges before disappearing.
Kaorinite will receive a Daimon pod from Doctor Tomoe and fuse it with an object to transform it into a Daimon. That Daimon will then use a star symbol on their body to extract Kaorinite's target's Pure Heart, as Kaorinite is searching for the three Pure Hearts that will summon the Purity Chalice, which Tomoe and Mistress 9 need to summon Pharaoh 90. All of Kaorinite's minions are killed by Sailor Moon with Moon Spiral Heart Attack except Mikusi, who is killed by Sailor Uranus and Sailor Neptune, although Senishenta, alone of all the monsters of the week, lasts two episodes, which happen to be two parts of one double-length episode.
- Die Heart
Eugeal (Eudial) takes Daimons in a box after Tomoe creates them with a Daimon pod and an object in his Heart Snatcher Oven. Unlike Kaorinite's Daimons, Eugeal's Daimons do not extract Pure Hearts. Eugeal does this using a kind of gun. When the Sailor Scouts intervene, Eugeal would send the Daimon after them. All of them are killed by Sailor Moon except Darumah, who is destroyed by Sailor Jupiter. Although Doorknobder is more or less killed by Eugeal, as Sailor Moon directed her Moon Spiral Heart Attack at her and she deflected it at Doorknobder.
- Ironder (only shown in flashback)
Mimet (Mimete) takes Daimons created by Heart Snatcher Oven in a briefcase to extract Pure Hearts from her targets, often attractive male celebrities. Although the Purity Chalice has already been revealed, Mimet's task is to collect Pure Hearts to feed to Mistress 9. These Daimons suck their victims' Pure Hearts out through their mouths. Most of Mimet's Daimons' names start with U.
- Western (U-Estern)
- Ikasaman (U-Ikasaman) (monster with her own agenda created by Mimet in a freak accident)
Doctor Tomoe is actually possessed by Germatoid, the king of the Daimons who serves Mistress 9 and Pharaoh 90, although Germatoid's servants do not realize this, as they know him only as Doctor Tomoe. Germatoid eventually leaves Tomoe's body but is killed by Sailor Uranus. He is the only male Daimon.
The remainder of the Daimons are shown in a raw, red form and attack the Sailor Scouts, even killing Sailor Pluto, until all but one are destroyed by Pharaoh 90 when he brings about the Silence. After Mistress 9 and Pharaoh 90 are killed, the last surviving Daimon merges with the Heart Snatcher Oven and becomes Rangy, who is destroyed by Sailor Moon with help from Rini. The Heart Snatcher Oven is destroyed shortly after.
- The Daimons are the only Monsters of the Week in Sailor Moon who are all female. There have been male Negamonsters (Leo the Lion, five of the Seven Shadows, plus male victims transformed by Zoycite and Malachite), one male Cardian (Vulturos), two male droids (Doom and Gloom, although they seem different from other droids), and every Remless who serves Fish Eye or Jun Jun is male, as well as Mr. Magic Pierrot (even though he serves Para Para).