Wax vegetables are a kind of vegetables, presumably made of wax. When a lit candle was poorly transfigured into a purple rabbit that ran away from the Transfiguration class, Harry Potter was put in charge of finding it. When questioned by Harry whether he had seen the purple rabbit, Rubeus Hagrid said he had seen it going towards the Greenhouses. He then speculated that the rabbit might have gone after the wax vegetables.