Lepraliella hippopus is an encrusting bryozoan that forms irregular colonies. The autozooids are hexagonal or with an irregular outline, flat or slightly convex. They range in size from 0.45-0.6 by 0.4-0.5 mm, with two oral spines visible in some autozooids at the periphery of the colony.
Lepraliella hippopus is a boreal-arctic species and its occurrence in Britain is uncertain. It was reported by Hincks (1880) off the coast of Northumberland, but was not recorded by other major surveys of British waters. If it does occur in the UK, the most likely habitat would be from the north-east coasts of England and Scotland.
The species is able to colonise stones, shells and Polychaete tubes. It is a subtidal species occurring in offshore waters of moderate depths.