1 cup crushed ice
1/2 cup pina colada mix
1/2 cup rum
2 cups caffeinated pepper-type soda (such as Dr Pepper®)
Combine ice, pina colada mix, and rum in a blender; blend until smooth, with no icy chunks, about 10 minutes. Divide between 4 glasses. Pour 1/2 cup pepper-type soda into each glass.