Bowser

King Bowser Koopa is a hulking, turtle-like creature who is the arch-nemesis of legendary video game hero Mario. This brutish villain has appeared in almost all of the Mario video games, whether as an antagonist, a playable character or simple comedy relief. Boasting great strength, magical talent and an endless army of creatures under his command, Bowser has made it his mission in life to take over the Mushroom Kingdom and marry Princess Peach. Mario continues to stand in the Koopa King's way, always thwarting his plans for world domination and always rescuing the Princess.

Background
Bowser is the king of the Koopa Clan and rules over the Dark Lands of the Mushroom World. He commands a vast army of multiple types of creatures such as Koopas, Goombas and many, many others. Throughout all of his appearances, he has had his sights set on conquering the Mushroom World, as well as other lands that have met his fancy. In the Super Mario Galaxy games, he even went so far as to try and conquer the universe by building a new galactic empire with the energy of the Power Stars. Aside from conquest, Bowser's other major obsession is Princess Peach. Every time he hatches a villainous scheme, he kidnaps her and holds her in his castle. The motivation behind these kidnappings has been vague for the most part, but later games have shown that Bowser has a crush on Peach and wants her to marry him. Though he claims to be infatuated with her, he has never shown any regard for her feelings or her safety, often putting her in mortal danger.

As well as being a ferocious would-be conqueror, Bowser also seems to be a family man. Frequently joining him in his schemes is his son Bowser Jr., and in the past he has also been aided by the seven Koopalings (though as of 2012, these Koopas have been confirmed as not being Bowser's children). But no matter how many creatures he commands or how deadly he makes his castles, he has always failed to destroy Mario and been defeated. Despite his long list of failures, Bowser is extremely persistant and refuses to give up no matter how often Mario foils his schemes.

Personality
Bowser is a greedy, self-absorbed, brutish and childish bully. He loves to boast about how awesome he is, despite the fact that his plans always fail and he can never seem to beat Mario in a fight, fair or otherwise. He is extremely quick to anger and has no patience for incompetent lackeys, yet at the same time he doesn't see the fact that many of his plans aren't thought out that well and lack creativity and originality, making him a rather predictable foe.

While Bowser is seen to be a power-hungry monster by most, there is a softer side to him, albeit a rarely seen one. At times, Bowser has allied himself with Mario and his friends to fight a greater evil. While he would claim that he is motivated by his selfish desire to conquer the world before someone else conquers/destroys it, Bowser has occasionally displayed genuine sorrow and outrage over some of the actions of other villains.

Powers and abilities
Fire Breath - Bowser can breathe fire like a dragon, a trait that has occasionally misled others into believing he is a dragon. He can spit fireballs or a long stream of flame as he chooses

Strength - Bowser is one of the strongest creatures in the Mushroom World and he goes out of his way to make sure everyone knows how tough he is. He frequently pits his brute strength against Mario by trying to pulverise him with his fists or crush him with body slam attacks. His spikey shell and horns also offer a high level of protection since Mario can't stomp on those. It's worth noting that (outside of the Paper Mario or Super Smash Bros. series) Mario has never defeated Bowser through brute strength.

Hammers - In some of his appearances, Bowser has also been shown to throw hammers much like his Hammer Bros. minions.

Size - Bowser's size has altered frequently between his game appearances, ranging from around twice the size of Mario to several storeys tall.

Dark Magic - Bowser has wielded many magical spells that have been key to several of his plans. Such magicks have included turning his enemies to stone, creating huge, imposing castles and weapons, and teleportation.

Weaknesses
As with so many villains, Bowser's greatest weakness is his arrogance. He is so certain of his success despite his countless defeats at Mario's hands and there is little variation in the way that he fights, so he frequently sets himself up for failure. His plans lack originality too as he always follows a particular trend of kidnapping Princess Peach and leaving a trail of traps and minions for Mario to overcome.