It should look like a single-ended creasing hammer
Axes and hammers have more or less the same weight distribution and the existence of throwing axes proves that the lack of center of gravity does not stop thrown distal heavy weapons from being viable. In fact, they are more viable than balanced or proximal heavy weapons because they are carried by the inertia of the weapon's head that follows a larger, and faster moving distal arch than your hand. Basically they follow the same principle as a sling.
Throwing axes like Francescas and Tomahawks were both very similar weapons despite coming from different cultures. This convergence of properties tells us that there is something about the qualities of a throwing axe that make them more ideal for throwing than their hammer-shaped counter-parts. In general, throwing axes are similar to 1-handed war axes, but they were normally much lighter weighing in at 250-850 grams vs melee war axes which averaged closer to 800-1500 grams. Throwing axes also frequently turn the blade down a bit to make sure it strikes in line with the spiral of the throw.
You can also note that nearly all throwing axes are single-bitted with relatively narrow striking surfaces. This is because the axe will never need to strike with the back or distal end the way you do with a melee weapon because there is pretty much just one right way to throw an axe/hammer, this allows you to make a long-as-possible head to make hitting on the handle less likely, and the narrow striking surface is important for getting adequate penetration since you can not drive a thrown weapon through with your bodyweight like you can with a melee weapon.
