The Flobberworm is a thick, brown magical worm that can grow up to ten inches in length. It is a simple creature, appearing physically identical at both ends, and is toothless. Its most notable feature is the constant production of a green, slimy mucus. This Flobberworm Mucus is known to have properties useful in Potions, such as for thickening draughts.
Flobberworms are herbivores whose preferred diet consists of vegetables, particularly lettuce and cabbage. They are exceptionally sedentary creatures, spending most of their time doing little more than eating and excreting mucus. Their lifestyle is so uneventful that the Ministry of Magic classifies them with the lowest possible rating, “X,” for “boring.” They thrive in damp environments like ditches and require careful feeding. Overfeeding a Flobberworm can be lethal, as seen during a Care of Magical Creatures lesson where Rubeus Hagrid's students gave them too much lettuce, causing the worms to grow excessively large and lie on the ground, twitching feebly.