Dry Bones is a minion species of Bowser that is essentially an undead Koopa Troopa. If jumped on, it will fall to pieces instead of hiding in its shell. They can survive in lava in a few games and are in Bowser's Castle. If they are jumped on and their head falls into lava, it will take slightly longer for it to reassemble. They can only die in a couple games where there are Ice Flowers. You must freeze them and then pick them up and throw them at a wall or in lava. You can play as Dry Bones in the Mario Kart series, the Mario Party series, or Mario Superstar Baseball.