The computer-designed objects called trajectoids follow a predetermined path when rolling, and usually look somewhat like peeled potatoes.
I haven’t seen a trajectoid with an obviously arbitrary, complex path, such as someone’s signature (as opposed to demos of epicycles), so there may be limits to what lines can be made.
I think the similarly-looking gömböcs are cooler: convex, uniform objects that always return to one stable orientation when laid on a flat surface.
Not entirely irrelevant to D&D. Now we know that a skilled scholar could sculpt a boulder to roll in a specific way (for an Indiana Jones-style trap) without casting spells. Still, adjusting the terrain is a more productive way to do that.
But they're not useful as dice. Nobody ever uses a die’s trajectory shape to determine a random in-game outcome.
A gömböc could technically count as the most rigged die – only ever rolling up one number – if the only requirements for a D&D die were for it to be a convex object with uniform density.