Chop the pineapple into small cubes, then place in a bowl and cover with rum. Store in the fridge for at least 2 hours to infuse the pineapple with alcohol. Drain pineapple. In a large bowl, empty the cream of coconut into a bowl, the top is solid and will look like candle wax, with coconut juice underneath, so don't freak out. Add the heavy cream and the sugar. Beat until fluffy and soft peaks hold, about 3 minutes. On a small skewer (or toothpick), skewer a maraschino cherry then a boozy pineapple cube. Dip the bottom of the pineapple into the coconut cream mixture, then dip in shredded coconut to coat. Refrigerate until ready to serve.