Combine pineapple and ice in a blender. Blend for 1-2 minutes until ice is crushed and drink is smooth.
Notes
Fresh, frozen (thawed), or canned pineapple all work well! If your pineapple isn't very juicy or you're using frozen pineapple, you may need to add a splash of liquid (water, lime juice, pineapple juice, or adult beverage if 21+).