Bubotubers were plants that looked like a large, black slug. They had shint protrusions on them, and when squeezed, pus could be extracted. Bubotuber pus was a valuable, thick, yellow-green liquid which smelt like petrol.

This plant acted both as part of the diet of a forest troll, and also - when diluted - as a treatment for acne and in the Healing Potion.