This could be one of any of a wide range of lesser intermediary spirits between their world and the physical world.
Demons play no role in neo-Pagan Witchcraft.
Demon is derived from the Greek term daimon, or divine power, fate, or god. Daimons were intermediary spirits between man and the gods.
A guardian daimons shared advice and ideas. It was considered lucky to have one for guidance and protection.