Zombone

Zombone is the skeletal counterpart and second form of the Czar Dragon. When Czar Dragon is hit enough times, it falls in the lava, loses its skin, and becomes its other form, Zombone. Zombone has plenty of dangerous attacks, such as sending out boulders to attack Mario, Peach, Mallow, Geno, and Bowser, or headbutting them. After the gang hits Zombone enough times, Zombone explodes and collapses into the lava, defeated.

While Zombone has stronger attacks than the Czar Dragon, it has less defense and a weakness to thunder attacks. It also loses the power to use fire attacks or summon Helios. Being also an undead enemy, Zombone is vulnerable to the Pure Water item. However, Pure Water only causes a fixed damage of 200 points to Zombone instead of defeating entirely, like other non-boss undeads.

Trivia

 * Czar Dragon's death and rebirth as Zombone is similar to Bowser's death and return as Dry Bowser in New Super Mario Bros.
 * Its name is a portmanteau of "zombie" and "bone".
 * "Zombone" was also the name of an enemy in the game Final Fantasy VI for the SNES, also developed by Square. The game's coding also contains a deleted superboss named "Czar Dragon."