oval, egg-shaped, ovate, ovoid

Prolate, ellipsoid, oval, ovate, and ovoid all can mean egg-shaped.
The word oval refers to objects that are egg shaped. It comes from the Latin word ovum, which means egg.

Ovoid means "seeming like an oval" or "egg-shaped."

egg shaped OR elliptical

A three dimensional oval is simply called an egg, or more mathematically, an ovoid. A three dimensional ellipse (a more symmetric oval) is called a prolate spheroid, or oblate spheroid, depending on how the ellipse is rotated.