Unicorn Nibbler Posted in U Best definition Unicorn Nibbler When you place your ball sack on someones forehead so that you penis protrudes like a unicorn horn. I was getting a blowjob the other night, and then just gave this chick the biggest unicorn nibbler. How satisfied are you with the definition? Looking for Unicorn Nibbler meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 79 times.