My players will soon be going into a dungeon that is an old abandoned dwarven mine. I plan to have there be a mushroom-like entity or something that has taken over the mine and is the reason the mine is abandoned. (invaded and killed a few of the miners) 

My question is if the mushroom entity uses its spores to grow fungus on the dead bodies and control them would they count as undead for the purpose of a cleric's Turn Undead feature?