A witch or wizard who studies magical plants and animals in their native habitats. A magizoologist is a type of wizarding naturalist who specifically studies animals.
Luna Lovegood became a wizarding naturalist upon leaving Hogwarts. She married Rolf Scamander, who also was a naturalist (BLC, NO).
Gwendolin Oliphant was an 18th century naturalist who studied trolls. Other famous naturalists include Quong Po, an expert in dragons, Havelock Sweeting who worked with unicorns, Beaumont Marjoribanks who classified many rare and magical flowers and plants, Gulliver Pokeby who was an expert on magical birds (FW), and of course the famous Newt Scamander, author of Fantastic Beasts and Where to Find Them (FB, FW, FB/f).
Was Professor Sprout a naturalist? Technically, a naturalist spends time in the natural habitat of the plants and animals being studied. We have no evidence that Sprout did so, instead spending her time in the greenhouses at Hogwarts. But who knows ... perhaps she spends July and August wandering the world in search of new and exciting magical plants. --SVA