Bubotubers are wizarding plants that produce an extremely valuable pus. They stick up out of the ground and look like vertical, wiggling, black, big slugs with several large liquid-filled shiny lumps. When these lumps are popped, a large amount of pus bursts out of them. Bubotuber pus is gross but useful—it is an excellent remedy for acne.
Harry Potter, Ron Weasley and Hermione Granger have a class about Bubotubers in greenhouse three, on September 2, 1994. Sprout instructs her students on how to squeeze them in order to obtain pus. The teacher warns them to use dragon hide gloves when handling Bubotubers, to prevent the unpleasant effects their pus can have on human skin.