A Unicorn is a gentlemen of African American decent that plays professional hockey in the United States of America. They are called such because it is such a rare occurrence to spot one in the NHL that their mythic status is often compared to the fabled Unicorn.
Bro #1: Bro we went to the hockey game and I saw a Unicorn
Bro #2: No way I thought those didn't exist
Cody: Well since its your first time there you will be considered a unicorn, so you will need to find another unicorn which is unlikely. However the cuckolds will allow you to do their wives.