In addition to being a member of a fairly unique genus and species, the famous hippopotamus (hippopotamus amphibiusis) is also the Tony Soprano of the African animal kingdom. That is, if you get in his way and irritate him, you're on you own, pal. In fact more people are killed by hippopotamus (the plural is a bit uncertain) than any other African animal.
This rendering is in water based clay, as an intermediate stage of creating a ceramic sculpture. In fact, this statue is at the "leather" stage, where the clay is firm enough to be handled with care but is still moist to the touch. At this stage of making a terra cotta - that is, fired clay - it must be - if not already - hollowed out. Hollowing is accomplished by cutting the statue apart, usually into two pieces, and removing the clay so the walls of the statue are about 1/2 to 3/8 of an inch. There are additional procedures needed to facilitate the removal of water, procedures which if not done properly can lead to the statue breaking or even exploding during firing. Obviously ceramics is not something to be attempted without professional instruction.