Living unseen servant

A living unseen servant was an unseen servant that had been conjured as a living spell in an area effected by wild magic. They served their master unerringly, as a sort of over-eager manservant or chambermaid.

Description
While they were typically invisible in appearance, as per their name, the use of certain divination spells such as see invisibility or true seeing shown them to have the form of a slender, adult humanoid.

As they were considered magical constructs, living servants were immune to poison, paralyzation, petrification and could not be rendered unconscious.