Adjunct

(Sometimes also "adjunct talent") A creature or other sentient asset cooperating with a wizard on errantry for the completion of a specific task. The adjunct does not itself have to be a wizard, but is normally at least competent in the Speech.

There is a specialist usage of the "adjunct" term which implies that the powers or abilities of the adjunct are at least partially due to the catalytic or partially catalalytic influence of another being, usually a wizard. This usage also implies a relationship between wizard and adjunct which can range from simple partnership to full symbiosis. (TWD et seq.)