After seeing a few photos online, I decided to dress up as a traditional donkey Pinata Costume. I bought a cheap sweatsuit, crepe paper, and two party hats and went to work with my hot glue gun. Row by row, I glued the crepe paper on, and then went back to fringe the ends. I made sure to leave the pockets of the sweatshirt open so I could stuff them with candy.
I had a stick (not picture: empty wrapping paper roll with crepe paper) and when someone wanted to give me a whack, I let them & then threw out candy. Make sure to use a hooded sweatshirt so you can glue on the paper hats as ears. This was a huge hit at work.