This makes an egg.

OpenSCAD module to make egg shaped objects.

Needs some work but IMHO it looks like an egg.

The parameter egginess effects the shapes propensity to look like an egg, with the value of 1 being most egg like.

If the term egginess is not precise enough for you, check this site as my formula is base on this decent explantion of an egg shaped curve.

http://www16.ocn.ne.jp/~akiko-y/Egg/index_egg_E.html