A bubotuber is a fictional plant in the Harry Potter series of novels by J. K. Rowling. They are thick, black, slug-like plants that extend perpendicularly to the soil. It is normal for them to squirm and they are covered in pus-filled swellings.

The bubotuber pus is described as having adverse affects when in contact with skin - dragon-hide gloves are worn. The pus looks yellowish green and smells of petrol. In a dilute form it may be used as a cure for acne.

In the Chamber of Secrets, many people got stoned and were saved with bubotuber pus.
In the Goblet of Fire, Hermione Granger receieves an envelope of Bubotuber Pus from an undisclosed person (possibly Pansy Parkinson) after Rita Skeeter publishes a story falsely stating that she is in a romantic relationship with Harry Potter. Receiving this envelope made Hermione walk around with bandages on her hands for a long time.

In the Half-Blood Prince, fifth chapter, Molly Weasley mentions bubotuber pus as an additional ingredient to gravy then sold by some as fake protective potion supposed to guard against Voldemort and his Death Eaters.