From Kimberly’s website:

I am constanting editing patterns and recipes to adjust for size and taste according to the person(s) involved. Thanks to the Pussy Hat Project, I was able to design and write a top-down hat pattern (soon to come!) that incorporates a more distinct pair of cat-like ears without any excess needlework (some knit separate ears then attach, others require additional sewing/seaming).

After requests on how I created these cat-ear hats, I realized a huge thought:

#I could add these ears to any beanie hat pattern, as long as enough yarn was available.

Please note your choice in yarn weight and gauge could affect ear size. In my top-down hat pattern, the ears’ section measured 2.75 inches using aran-weight The Fibre Co. Arranmore yarn. In the bottom-up incorporated ears in ArtYarns Super Merino’s worsted weight, they measured 2.5 inches. I used about 15 to 20 grams in the ears section.