There are a variety of minor infernal celestials, who are Hellish spirits lesser than demons. They are commonly referred to as "demonlings." While seemingly inconsequential, prudent demons know to keep an eye on them at times ... Haagenti started as a demonling, after all.
Demonlings who claw their way up the ladder typically "fledge" into demons at 7 Forces, earlier than Relievers, who require 9 Forces to become a full angel. This reflects the fact that Hell is more interested in quantity than quality.
Imps are minor celestials who specialize in harassing humans.
Gremlins are minor celestials who wreck places or things rather than focusing on specific people.
Familiars are particularly unfortunate creatures, who have animal vessels and are owned by a demon. They can be used to store Essence, to perform minor tasks, or be given a demon's Discord to temporarily relieve the demon of its effects. They receive dissonance for disobeying their masters.
Fledge to: Any