Kingfin

Kingfin is a boss in  Super Mario Galaxy. It is a giant skeletal shark, living in the Bonefin Galaxy.

Kingfin has the power to summon large hoardes of angry Fishbones from the craters in the center of the planet, which attack in the same way as Torpedo Teds, homing in on the player from all directions. The more damage Kingfin takes, the more Fishbones it will summon to attack Mario.

Kingfin appears to be a gigantic fish made completely of bones. It also, fittingly, bears a resemblance to a Fishbone.

Battle
When Mario enters the waters of Kingfin's planet, Kingfin will appear with some Fishbones that track Mario down to attack him. There are only two ways for Mario and Luigi to defeat these Fishbones; they must lure them to the surface or into a wall, or throw a shell at them, which causes them to drop three Star Bits upon impact. If the fish touch the surface they will automatically explode. If Mario touches Kingfin, he will lose health. The only way to defeat Kingfin is to grab a Green Shell or a Red Shell from the seafloor of the planet and spin to launch it at Kingfin. After one hit, two Fishbones will attack Mario. After two more hits, four Fishbones appear to attack him. Once Kingfin has been hit a total of five times with shells, he will explode and release a Power Star. The battle can be made easier with the help of a Life Mushroom hidden in a pillar, as well as a submerged treasure chest, which contains the only 1-Up Mushroom in the level. The pillars are destroyed by Kingfin ploughing through them; he destroys two shortly after getting hit once, and he destroys two more after taking another two hits.

Trivia

 * Kingfins's name is most likely a pun on the word "kingpin," which means: "The most important person in an undertaking or organization".
 * In the Prima Game Guide book, an issue of Nintendo Power, and in his Super Mario Galaxy Trading Card, he is mistakenly called "the Bonefin". This is probably due to the fact that the galaxy in which he resides is called "Bonefin Galaxy."
 * The theme music in the battle with Kingfin is the same with Bouldergeist. However, when Mario or Luigi come closer to Kingfin, a percussion beat is added to the background music. The music speeds up once Kingfin has taken damage three times.
 * Although Kingfin looks like a skeletal shark, in the real world sharks have no skeletons at all; they are cartilaginous. Therefore, Kingfin may possibly be another species of fish, possibly a giant Fishbone.
 * Kingfin is the only boss in Super Mario Galaxy that appears in a bonus galaxy.
 * Kingfin is the boss with the second largest amount of hit points in Super Mario Galaxy, with a total of five. Bowser from Bowser's Galaxy Reactor has six.
 * Kingfin may be part robotic, because his eyes are lights, and when he has one hit point left, electricity can be seen surging around his body.
 * Kingfin's eyes do not shine beams of light if the player is playing as Luigi; the eye beams are only present when Mario enters Bonefin Galaxy.