It's called Stinkhorn fungus - and apparently it really smells bad.
Melbourne Museum staff have found a rare Stinkhorn fungus growing at the base of a tree fern in the building's Forest Gallery, at inner suburban Carlton.
"The Stinkhorn fungus (Pseudocolus fusiformis) is found in the wetter forests of Victoria, where it is quite rare, and also in New South Wales and Queensland," museum spokeswoman Jessica Bendell said.
"So far the fungus has been recorded in only four locations in Victoria, including the Otways and the Dandenongs.
"The Forest Gallery find is the first time it has been recorded in metropolitan Melbourne."
The Forest Gallery is a living interpretation of Victoria's tall temperate forests, and houses approximately 8,000 trees and plants, from more than 120 different species.
The Stinkhorns use foul-smelling slime to attract flies and other insects, which then land on the sticky substance.
The insects' legs are then covered in slime containing spores, which are then dispersed by the unwitting insects.
The fungus can be seen or smelt from the Forest Gallery's "Earth" pathway for the next few days only.