Dry Bones are enemies who are bony, skeletal, dried out, undead, Koopa Troopas. Dry Bones first appeared in Super Mario Bros. 3 where they, like their kindred, walked on four legs. In later games, Dry Bones and their living counterparts would start to walk on two legs, starting with Super Mario World for the SNES.
In the Paper Mario series, Dry Bones appears as an enemy, usually found in the later, if not last, dungeons. In Paper Mario, Dry Bones appears within Bowser's Castle. Several can be found throughout the second half of the castle, and, in this game, the Dry Bones can't be defeated regularly. Dry Bones can be "defeated" by regular attacks, but after a few turns, so long as other enemies still stand, the Dry Bones will rise up and begin fighting again. However, if a Dry Bones is defeated with a fire-based attack, he'll be hit with a critical hit maximizing in 16 points of damage, more than enough to defeat him. The body burns when hit by a fire attack, so it doesn't get the ability to rise back up. If a Dry Bones isn't defeated in this manner, no Star Points will be given to Mario.
In Paper Mario: The Thousand-Year Door, Dry Bones appear in the final dungeon, the Palace of Shadow. Here, Mario first encounters a few in a large circular room, and then later throughout the palace. Dry Bones, in this game, are very similar to their Paper Mario counterparts, but they have a more dangerous ability to build a new ally when the time comes. They can do this attack anytime for their turn, so long as there's no more than five people on the enemies' side. Dry Bones also appear in the Pit of 100 Trials, during floors 50 to 60. Like most enemies, Dry Bones will sometimes appear in the audience, and sometimes will throw a bone at Mario or his partner. In Paper Mario: The Thousand-Year Door, also, there are subspecies of Dry Bones that appear, Red Bones, Dull Bones, and Dark Bones. The Dry Bones are the second strongest species in the game with the strongest being the Dark Bones.
In Super Paper Mario, Dry Bones will attack similar to how they do in the first two Paper Mario games, they'll throw bones and bump into Mario. They're less of a threat than they are in the previous game, but there are also less ways of defeating them. Still, they go down onto the ground upon losing their HP, but they aren't defeated until unless felled with a fire-based attack. Dry Bones, and Dull Bones both appear in the Underwhere, during chapter 7 and Dry Bones will also appear in the Flipside Pit of 100 Trials. In the Flopside counterpart, like with all enemies, there is a dark counterpart of the enemy.
In Paper Mario: Sticker Star, Dry Bones only appear in World 2. They attack mainly by hurling bones at Mario. Unlike all of the other Paper Mario games, even when the Dry Bones are defeated in battle, their bones will remain on the ground and after a few seconds, they will get back up on their feet to battle Mario again. However, in certain rooms of Sandshifter Ruins, Dry Bones will remain on the ground as long a nearby torch remains unlit. They sometimes drop Bone stickers when defeated.
Super Mario Galaxy
In Super Mario Galaxy, they make a new appearance, but it's limited to desert places and the Bowser's Galaxy Reactor, in the gravitational spotlights part.
Destroying them, however, needs from Mario to be in his Rainbow Star form, leaving three Star Bits when destroyed. They can also walk into quicksand if executed properly otherwise it is fatal.
In Mario & Luigi: Dream Team, Dry Bones also appears as enemies in this game but they are only fought during the second battle with Kamek in Dreamy Neo Bowser Castle. They also appear in groups and they mainly attack by charging and throwing bones at Mario. After they have been defeated, Mario can use their remains to damage Kamek.
All Dry Bones can be capable of rebuilding their bodies after being hurt. This outstanding process takes place only a few seconds after being stomped on. The player can defeat Dry Bones for good, but it takes magic, bombs, an ice flower or Penguin suit, shell collision, or a possession of a star to do so. You can also break him and knock a body part off to a lower ledge or lava, but the remains won't stay permanently. While in the mainstream series, Dry Bones are immune to Fireballs, Dry Bones are also very susceptible to fire-based attacks as shown by how in Paper Mario, fire attacks are super-effective against them..
"I'm totally starving! Seriously. I mean, just look at me! I'm down to bones over here!"