Typical traditional Japanese roof decoration, the Onigawara (鬼瓦): it's a tile shaped as an oni (鬼 - ogre like character) and goes at the end of the roof ridge. I've sculpted the oni in zBrush after preparing a few base shapes using curves and surfaces in Maya. Paradoxally, the most difficult part for me was the decoration that goes under the demon and not the demon itself. For that I had to use Maya to bake a base mesh and, then I've finished the whole thing in zBrush (see breakdown screenshot). This decoration under the demon is far from being perfect, but it's decent.
More about my work on traditional Japanese roofs:
Roof generator BP https://www.artstation.com/artwork/RyLWzr