A Purple cow person doesn't have a resume. His remarkable achievements speaks for him. In fact, he doesn't need a resume because people find him easily without one.
A purple cow person is specialized in a sub-sub-sub field and he is really good at it. Not only that, he is remarkable because nobody does it like him. (And certainly am not talking about Chili's)
A purple cow person doesn't aim for everything, he is bad at that. That's the main reason he is good. Once everybody started to do what he does, the purple cow person is finished, he will just be a cow. A boring one.
How to know if you are a purple cow person?
If people are talking about IPhone Games Programming, the first person comes to their head is the purple cow person at IPhone Games Programming.