It's basically your Puerto Rican version of moonshine. It's made by with different fruits and rum. The items are mixed together and buried underground to cure and age. Sometimes it's made with other items like cheese. I remember the first time I had this, I took a shot and I was immediately drunk. And yes, this Puerto Rican moonshine is illegal. Oh, and it tasted foul.
My first time I had 4 different flavors. Cranberry, Guava, Coconut, and Pinapple. They tasted amazing. . . Don't know how I made it home that morning lol.