He was created by the Ancients, but was locked away, presumably due to being evil. He claims to be a god. He is a mechanical dragon like Fracktail, but talks regularly rather than like a computer. Mario, Princess Peach, Bowser, and Luigi got to the bottom of the Pit of 100 Trials and fought Wracktail. They defeated him, and he was destroyed, exactly the same way as Fracktail before him. But before his death he said that greater challenges awaited in the Flopside Pit of 100 Trials, and that he wasn't the only one created by the Ancients.
The reward for beating Wracktail was the speedy Pixl, Dashell.
Wracktail has an attack power of 10. It is unknown what his HP is, but is presumed to be over 200. His fighting style is exactly the same as Fracktail's; he will fly around for a while in the background and then come in and attack the player, who can avoid him by moving as he comes in for the attack. Wracktail will then fly to the right of the screen, then charge at the player, who must, as Mario, flip to 3D and jump on his back. The only real difference aside from ATK power and HP is the Wrackles, which can shoot projectiles. The player can use Thoreau to throw the Wrackles at his antenna or, for an easier victory, have Luigi use a Super Jump on his antenna and continue to bounce on it. After losing a third of his HP, Wracktail will fly in a loop. The player can jump off his tail and land on his head at the right moment; otherwise, he/she will have to get on his back the same way as before to damage him again. Jumping off his tail onto his head as Peach is easiest, and if she is high enough she can land on his antenna and do more damage.