Baby Luma

Luma is a major character in the game Super Mario Galaxy. Like many Mario characters, he is named after his species.

Background
Luma's story begins when he was separated from his mother. He finds young Rosalina and asked her to help him find his mama. Rosalina repaired a rusty, old ship and together, she and Luma began a long search for his mom. One day they found a comet which Luma said his mother traveled on. However there was no sign of Luma's mother. Rosalina and Luma finally gave up hope of finding Luma's mother. However, Rosalina soon discovered that buried in the comet are tools and building material. Together, the duo built a small settlement. After it was completed, the building seemed rather big for just two people. Not long after, another Luma appeared traveling on a comet. Luma and the newcomer fought over Rosalina's love. More and more Lumas flew out of the comet shouting "My mama" at Rosalina. Rosalina adopted all the Lumas and became their mother. One night Luma found Rosalina crying and comforted her, asking her why she was crying. Rosalina told Luma that her mother is dead and even though she knew, she refused to believe it until then. Rosalina thanked Luma and the two hugged each other.

Later on, Luma transformed into the Comet Observatory to provide a new home for the Lumas and Rosalina. However he was re-born and nurtured for by Rosalina until he became a full grown Luma again.

Super Mario Galaxy
Sometime later, Princess Peach found Luma and planned to give him as a present to Mario. However, just as Mario was arriving, Bowser kidnapped Peach by hoisting her castle into space. Luma escapes to a nearby planet in the Gateway Galaxy. Meanwhile, Mario is attacked by a minion of Bowser and sent to the Luma's hiding spot. Luma and his friends convince Mario to play a game of hide-and-go-seek with them. When Mario finds them Rosalina appears and tells Mario that in order to save Princess Peach, the now broken Comet Observatory needs to be fixed using Grand Stars so it can fly to where Bowser is keeping Peach. Luma decides to help Mario and, bestowing Mario the power to Spin, the two begin the hunt for the Grand Stars. Traveling from galaxy to galaxy the two track down the Grand stars and slowly, the Comet Observatory becomes more powerful.

When the last Star is recovered, the Comet Observatory flies to the center of the universe where Bowser has created a huge sun. After a final duel, Mario and Luma defeat Bowser, destroy the sun and rescue Princess Peach. However, Bowser's dying sun creates a huge black hole and all the Lumas including Luma fly into it to stop it. Before being destroyed, Luma waves sadly goodbye to Mario and then dives. However, it is revealed Luma has been reborn, as all Lumas do, on another planet and is waiting for Mario's return. In the very final cutscene of the game, Luma can be seen in his and Rosalina's ship, waving at the camera and then flying upwards.

Super Mario Galaxy 2
Luma's reappearance in Super Mario Galaxy 2 was confirmed in the first trailer for the game. Luma can be seen popping out of Mario's hat as he performs a Spin, just as in the first game. He is found by Mario, who lets him tag along to Peach's Castle in his hat, as in the first game, which again grants Mario the ability to spin. After that, Baby Luma, as he is referred to in this game, continues to aid Mario just as how he did in the first game.

It's possible that this Luma is the same one from the prequel. This possibility is also strengthened as the player progresses through the game; the Luma will end up receiving letters from an anonymous person, but the player does get some hints as to who sent it.

In the ending, the Baby Luma eventually gets reunited with Rosalina and the Comet Observatory. He promises that he'll never ever forget about Mario, and as a result, took Mario's cap as a souvenir.

Trivia

 * In the beta version of the game Luma was called Tyke.