User blog comment:Derax-Pagani/Chapter 502 Review/@comment-26184007-20160917134307/@comment-24039234-20160919194841

It's a tattoo of Happy he tries to hide. He got it when they were on Caracole Island and the team forgot to order Virgin Mango Gelato. They got smashed, a few things happened, and they agreed to never speak about that island ever again.