Using a blender or hand immersion blender whiz together watermelon, strawberries, lime juice, a pinch of salt and mint. Pour into molds and fill about ¾ full. Place in freezer for 30-40 minutes.
Remove from freezer and place popsicle sticks in middle of each popsicle. Return to freezer for another 15 minutes. Remove and pour coconut milk to the top of the mold. Place back in freezer, cover with tin aluminum foil and let set up at least 12 hours.