Coriocella hibyae, common name the Hiby's coriocella or the velvet snail, is a species of sea snail, a marine gastropod mollusc in the family Velutinidae.

Although it has a shell, the shell is hidden within folds of the mantle, and overall the creature looks more like a sea slug than a snail, but in situ its external appearance resembles that of a sponge, which makes it difficult to spot underwater.

[1] This species can reach a maximum size of 10 cm in length.

The body coloration varies from slate-blue to dark brown, with some small round black spots which is part of what makes it look like a sponge.

A fragile ear-shaped shell is hidden inside the fleshy mantle.