They aren’t actually a race or anything of the sort. Wizzrobes are zombified wizards and witches who have been “brought back to life” through the use of necromancy. Commonly practiced by cultists (usually those loyal to Demise, but that isn’t necessarily the requirement), Wizzrobes are useful due to their powerful magic but they largely lack agency and intelligence on their own, which in turn makes them perfect for mindless drones for an army.
Like most zombies in Hyrule, Wizzrobes will act entirely on instinct if the caster doesn’t give them a “puppeteer” spell to fully control them, and when they run on instinct they are unpredictable and dangerous to handle. They have the same cravings as zombies with the added bonus of being able to use magic to achieve it: flesh of the living. While cultists do prefer a Wizzrobe they can order around, it isn’t uncommon for particularly cruel ones to simply reanimate a wizard’s corpse and let it loose into a village: the resulting carnage is always horrific if it isn’t stopped in time.
Hope that answers your question! <: