Hippo's mouth was firstly made to practice more detailed sculpting, however as I was satisfied with the result I went further with it by making retopology of the sculpt, baking normal maps from high poly (sculpt) to low poly model (retopo) and painting textures on the low poly model.

Sculpted, modelled and rendered in Blender (Cycles).
Textures painted and post-processing in Photoshop.