Bowser is said to be "King of the Koopas", the race of turtle-like creatures that co-exist with the Toads that inhabit the Mushroom Kingdom. In many games, particularly the RPG series, there are some Koopas who tend to be friendly towards Mario, whereas the Koopas that are evil or are followers of Bowser are labeled "Koopa Troopas".
Bowser is most well-known for his repeated kidnappings of Princess Peach. The reasons for these kidnappings have changed dramatically over the years, from the fact the Princess is the only one who can undo Bowser's black magic, to the possibiliy that he has some love and devotion towards her, such as in the original Paper Mario. No matter what the motive, he can use her to take over the Mushroom Kingdom or, in some cases, the world or the universe. In one of his greatest conquests, Bowser won the trust of the Goomba race by promising them that they would receive more of the Mushroom Kingdom if they gave him their undying allegiance and made him their leader.
Although Bowser is the main antagonist, he has allied with Mario in a few games. In games where he teams up with Mario to face a common enemy, he is often arrogant and egotistical, often joining for selfish reasons (such as to get his castle back from invaders or retrieve Peach's stolen voice so he can kidnap her again).
Early on, Bowser was solely created as a monstrous main villain. However, as video game technology improved, Bowser developed a deep, comical personality, namely in RPGs like Super Mario RPG: Legend of the Seven Stars and Paper Mario. Bowser is depicted as being fixated on defeating Mario, but also as an oafish, blustery character with no other plans than kidnapping the Princess and waiting to defeat Mario. He also appears to be blindly confident in his own chances of victory and sometimes jealous of other villains when they come up with evil plans more complex than his own. In a number of games, although Bowser is shown to hate Mario, he in fact possesses a degree of respect for him, and even appears as a playable antihero.
Bowser's appearance has been tweaked several times throughout the series, but most of the basic overall look has been consistent. Early versions were more turtle-like, resembling a large Meiolania standing on its hind legs, and with all the attributes of other enemies combined (fire spitting, spines and hammer throwing). Later revisions gave him a much more bipedal, draconic appearance, with an alligator/big cat-like face and powerful fire breath. Bowser's size tends to vary from game to game, sometimes only slightly taller than Mario (mostly in sports and spin-off titles), and other times being enormous (mostly in the main titles), though he is usually at least seven feet tall. Bowser's abilities vary greatly. His most common physical traits are the ability to breathe fire, spinning around at Mario inside his shell, and being extremely resilient. He is generally immune to standard attacks. His mobility varies greatly—in games where Bowser is a non-playable character, he is usually more agile and faster than Mario. Conversely, when Bowser is playable, he is often much slower than Mario. Outside his common abilities, some games give Bowser unique attacks; unique in that the attacks are not in other games—such as being able to create shockwaves or flaming boomerangs. Bowser also has sharp claws and a spiked shell, which often play into his arsenal of weapons.
Bowser has eight children. Seven of them, the so-called Koopalings, debuted in Super Mario Bros. 3, where they function as bosses at the end of every one of the game's worlds. Each Koopaling has his or her own airship, which are levels where the player has to navigate through before encountering the Koopaling. The seven kids reappeared as bosses in Super Mario World (having castles instead of airships), Mario Is Missing!, Yoshi's Safari,Hotel Mario and Mario & Luigi: Superstar Saga, where they played the role of minibosses . The Koopalings made their 3D model debut in the recently released New Super Mario Bros. Wii. Super Mario Sunshine introduced an eighth child, Bowser Jr., who wreaked havoc on Isle Delfino. Post-Super Mario Sunshine, Bowser Jr. continues to play a role in his father's evil schemes, and is the main antagonist in New Super Mario Bros.
is a Dry Bones version of Bowser. It first appeared in New Super Mario Bros.. It was a boss in after Bowser fell into lava earlier in the game. It has also appeared in Mario Kart Wii as a playable racer.In New Super Mario Bros., to defeat the skeletal monster, Mario must dodge Bowser's attacks, which include breathing small
flames and throwing his own bones, and wait for Bowser to make a high jump. Mario must then run under Bowser and hit the Skull Switch, destroying the bridge and throwing Bowser into a very deep pit. This battle is very similar to the battles against Bowser in worlds 5-8 of Super Mario Bros.; however, in that game he threw hammers instead of bones.
At the final battle of the game, the remains of Dry Bowser were thrown in a cauldron (the contents of which were unknown) which turns Dry Bowser back into his original form, except much larger, as if he had used a Mega Mushroom.
Bowser confronts Fawful again in Peach's castle, who was in the process of absorbing the Dark Star's power. Bowser fights and defeats Midbus once again. He also inadvertently inhales the Dark Star, which proceeds to copy Bowser's DNA, then exits his body and forms into Dark Bowser. Bowser tracks down Fawful and finally defeats him, reducing him to a small, black blob. Dark Bowser then inhales him, and with his power complete, Dark Bowser blankets Mushroom Kingdom in darkness. Bowser engages Dark Bowser in battle, and ends up inhaling Fawful. Mario and Luigi defeat Fawful from within, and Bowser defeated Dark Bowser and light shines upon Mushroom Kingdom again.