Megaleg

"Go at 'em Megaleg! Stomp 'em with the power of your Grand Star!"

- Bowser Jr.

Not to be confused with Digga-Leg.

Megaleg is one of several bosses in Super Mario Galaxy. It somewhat resembles a gigantic mechanical Snifit. It is found in Bowser Jr.'s Robot Reactor and is owned and possibly commanded by Bowser Jr..

Appearance
Megaleg is incredibly large and lives on a planet just big enough to hold it. It has three long legs, like a tripod, and each leg has various tricks and traps designed to trip Mario up. It has a Snifit-like face and fly-like eyes with huge lights beaming out of them. On top of Megaleg's head is a red cage with a rotating lighthouse-like light on top that contains a Grand Star. Megaleg is much bigger than Digga-Leg, a similar boss encountered in Super Mario Galaxy 2.

Combat
When Mario enters Bowser Jr.'s Robot Reactor, Megaleg is positioned on the bottom of the Robot Reactor. When Mario uses the Launch Star on the Starting Planet to reach the Robot Reactor, Bowser Jr. appears and orders Megaleg to attack Mario. Megaleg mainly attacks by consistently firing multiple Bullet Bills from various locations on its head, legs, and underbelly. It also tries to stomp on Mario while he's on the Robot Reactor. Mario must jump on one of its three huge feet and climb up its leg, avoiding Bullet Bills along the way. When Mario reaches Megaleg's head, he has to lead a Bullet Bill into the larger cage surrounding the red cage, after which a barrier forms around the red cage and more Bullet Bills are fired. Mario must then lead another Bullet Bill into the red cage to release the Grand Star trapped inside and defeat Megaleg.

Trivia

 * Megaleg underwent several changes prior to the release of Super Mario Galaxy: it was originally encountered in the beta version of the Good Egg Galaxy, at which point there was nothing in its cage and it was called "Snifit Bot". The earliest beta version of Megaleg was known as "BossCrab", which had a different body design.
 * The concept of climbing atop and moving on a large being was originally intended to be used in the final fight against Ganon in The Legend of Zelda: Ocarina of Time, though this was scrapped due to the fact that one would be unable to see Ganon while atop him. It was later reused in Super Mario Galaxy, much to the excitement of the development team.
 * Megaleg's design and functions have some similarities to the original design of the Tripod Walkers from H.G. Wells' novel, "War of the Worlds", such as having searchlights for eyes and three legs.
 * All of the other bosses in Super Mario Galaxy resemble another enemy in the game to some extent. Since Snifits don't appear in the game, Megaleg is the only boss that does not resemble another enemy. However, Digga-Leg from Super Mario Galaxy 2 looks almost identical to Megaleg, though it's different in size.
 * In a Nintendo Power interview, it was stated that Megaleg would return for Super Mario Galaxy 2. This was later proven false, with Digga-Leg appearing instead.