I had my Marvel Legends Black Bolt sitting there on my desk and I thought, "He needs his crown." So I whipped one up based on the original Jack Kirby design, although I did have to tweak the design slightly to get it to actually rest on the figure's head. It will likely need to be scaled if you want to use it on another figure.
It is relatively delicate and requires supports, so do be careful when removing them.
Inhumans_Crown.stl | 838.9KB |