Roof ridge finial

Glazed ceramic ornaments like this were placed at the ends of the ridge of a steeply pitched roof, helping to give the building the complex and spiky silhouette usually favored in Thai architecture.

The half-figure of a heavenly being with hands together  in a respectful gesture appears frequently in Thai art.
When such figures decorate temples, they suggest  that the heavenly beings are flocking in to worship the  Buddha inside.