When I brought out the Dwarven Battle Bonnet pattern a couple of years ago I had no idea it was going to appeal to as many people as it has. Clearly its not just me that firmly believes that everyone needs a silly hat in their lives.
One of the really great things about having the pattern out there being made by all sorts of people is seeing the variations on the basic pattern that people come up with, and it is a pattern that lends itself well to being modified slightly to create different character looks.
For example, here's one I made for a client last week, its got a spangenhelm/spectacle helm variation made simply by adding extra strips to frame the eye area, and 'rivets' added to the helmet by knitting a basic bobble at intervals, and hey presto, a completely different look for not much more effort.
If you have a look over on Ravelry at the projects page for this pattern, you'll see variations with horns on the helmet, different beard treatments, all sorts of different yarn choices, and lots and lots of really fantastic photos of people in their battle bonnets. I love creating hat patterns :)
If you fancy trying it out yourself, the pattern can be bought via Ravelry for just $3.00