Captain Skull
Captain Skull is an undead pirate that appears in Wario World. He is holding the last Giant Treasure Chest Key and is the last boss before the final boss. He has a cannon for one arm and an extendable hook on the other. The hook can be used to get Captain Skull from one side of the ship to the other with ease.
Wario battled him on a ship broken into two parts. Each half has a main deck and a crow's nest. An energy ring spring catapults Wario high up to the crow's nest. Wario can also manually climb there via a ladder. The two halves of the ship are separated by dangerous water, but fortunately, a stone slab can be used to cross, though it is easier to just use the energy rings.
Being the second-to-last boss, he has quite dangerous attacks, but all can be handled and dodged with ease. Captain Skull may fire multiple flaming cannonballs at Wario from the cannon on his arm. The cannonballs pose a danger even after they've cooled, as they can still explode. Captain Skull can also shoot blue beams at Wario, as well as his dangerous pink energy balls that home in on the anti-hero. But when lightning crackles from that cannon, Captain Skull will launch a gigantic moon that explodes on impact! Wario should be on the crow's nest if Captain Skull aims for the main deck and vice versa. Finally, Captain Skull's only close-range attack is a lunge at Wario that leaves him stunned long enough for the captain to make a getaway.
To defeat this boss, just punch him. He'll get dazed and Wario can use a powerful move to knock off a health skull. Once Captain Skull has been damaged enough, with only two health skulls left, he'll become invincible to Wario's punches. The only thing that can hit him now are his own cannonballs. Scoot over to the other half of the ship, dodging his attacks. When he starts flinging cannonballs, grab one, Power Throw it his way, and leap over to the dazed boss. Do a Piledriver or Wild Swing-Ding to knock out another health skull. Repeat once more to make him as good as dead. Or deader, as the case is.
When Captain Skull is done for, Wario receives the fourth and final Giant Treasure Chest Key.
But wait! This wasn't in the manuel! There's an easier way to knock out Captain Skull during his invincibility! Why waste time (and your health bar) trying to grab a cannonball that'll detonate in your bare hands when you can simply pick up a barrel before Captain Skull blows them up and hit him with it. The best way to do it is by Piledriving it on his noggin.
Captain Skull is possible the same guy as Skull Pirate, a boss from Wario Land 3.
