The Lanx: Vampire Potatoes?

First originated in Peru, the potato is one of the world's most favorable vegetable that comes in many different forms including the famous french fry and the potato chip. Though can be dangerous due to being related to the nightshade family (some examples include wolfsbane, tobacco, and tomatoes), the potato has a far-off, supernatural cousin called the Lanx. The Lanx is referred as "a potato on the outside, but a vampire on the inside" by Monstrologists. Though closely related to the Grool, a supernatural species of land sponge that feeds off of bad luck, the Lanx is far more dangerous than it's cousins. Being vampiric, the Lanx uses it's frightening teeth to attach themselves onto their victims ( which is usually on the victim's back). Not completely sessile, the Lanx can move by rolling their potato-like bodies to areas where potatoes grow to hide amongst them. Waiting for a perfect victim to pass by (such as a human or farm animal), the Lanx will attach itself and won't let go until it drains all the life force. After feeding, the Lanx will be larger and darker in color. The only known way that someone can remove a Lanx before it can successfully drain its victim is by pouring large amounts of oil over the creature to lose it's grip on the victim's body or limb.
The Lanx is a parasite and must feed off of hosts to survive. A potato pile like this can hold a very dangerous creature that can kill anyone if not removed. Though they too originated in Peru, the Lanx follows wherever the potato goes. Lanx, unlike the potato, tastes bitter, bloody, and can cause food-borne illnesses.