A new kind of animal has just been discovered under a flowerpot in Wales. It's been called the ghost slug, and it is unusual for several reasons. This slug is large, reaching 6 or 7 cm in size. It has no eyes, and is white in colour. It is active at night, and unlike the majority of slugs, it is a carnivore, feeding on earthworms using its blade-like teeth. The species was unknown to science before 2006.

The first ghost slug was discovered in 2006 in Glamorgan, Wales, and was formally described and named in 2008 by Ben Rowson at the National Museum of Wales, and Bill Symondson, an ecologist at Cardiff University. Because of the slug's white colour and nocturnal habits, and because it has been so rarely seen, it was given the species name ysbryda. The word "ysbryd" means ghost in the Welsh language. This in turn gave rise to the common name, "ghost slug". This appears to be the first case of an animal being given a name from the Welsh language.

Slug species like the ghost slug are more commonly found in Turkey and Georgia; however, the ghost slug is different from all of these. It is also the first slug of this kind to be found in Western Europe. Although the ghost slug is almost certainly not native to Wales, where the ghost slug came from and how it made its way into Britain is still unknown. Bill Symondson thinks that the slug probably originally lived deep inside caves because it is completely white and has no eyes, and may have arrived in Wales in the soil of a potted plant.

The first ghost slug was found in a lane in Caerphilly on October 29, 2006. This single specimen was photographed and then released. A year later, another slug was found by a gardener near Cardiff, Wales, where it was brought to the attention of the National Museum of Wales. Additional ghost slugs have been found in Gorseinon, near Swansea, Wales.

The ghost slug is not harmful to humans, but because it is an introduced species, scientists are asking the public to tell them any time they see one of the slugs. Scientists want to make sure that the ghost slug does not spread and eat so many earthworms that the earthworm populations get smaller, because earthworms are important for the soil and the environment.