I designed some cat ears and a bow (based on Hello Kitty) for my wife's Pro-Tec snowboarding helmet, size small.

The ears and the bow are separate files, so you can just add cat ears to your helmet if that's all you want.

I'm also including the two prior test models I made and printed during my initial sizing and design. You'll see that 'Test1' doesn't have a lot of detail. Test1 was really an initial design and more of a test fit to the helmet. I discovered that the ear went too far back and I needed to decrease the radius of the curve that controlled how quickly it dipped.

'Test2' came with some more refinement on the overall look. I shortened how far back the ear went, and added some curvature to the ear profile. The rear end of the ear still didn't follow the curvature of the helmet perfectly. The gap was really small though. But a perfectionist is gonna perfect. So, I still had to tighten up that. However, it's a great look and I wouldn't be sad to have stopped there. My wife only asked for cat ears. I just like taking things the extra step. Maybe 'Test2' is good enough for others out there.

The 'Final' model, which was originally named Test3, had fillets added along with a recess in the forward face to give off more of an 'ear' appearance. When I fit it too the helmet, there was still a little bit off, but I knew that I was gonna use double sided tape anyways. So, if I wasn't going to care about the gap that would come from the double sided tape, then I shouldn't care about the small gaps I had left. It was 'good enough'.

The bow was a really quick hack job. I just traced the bow from a .png image offline in Fusion and then extruded and finished with some nice fillets. I think I could have made it thinner or more refined, but honestly it was good enough also. Just superglued it to the ears that I taped to the helmet, and it was good to go.

Overall, it was a fun task I made for myself, and the final product is cool.