This is, I think, a section from a two-piece primitive wooden chair. Hand carved from an unknown wood. It seems to be African, but I can't say for sure. I believe this is the seat section, rather than the back. The narrow part would fit through a slot and form the back "leg" of the chair.
The carvings may represent lizards or frogs. The other side is blank.
It could also be used as a wall plaque, and has a metal hanger on the back for that purpose.
Length: 30"
Width (at the widest point): 15 1/5"