Toad Brigade
The Toad Brigade is a group of five Toads who aid Mario in Super Mario Galaxy. It seems likely they are the Toads who first accompanied Mario and Princess Peach to Isle Delfino in Super Mario Sunshine where they had minor roles and didn't have their own personalities. At this point in time, though, they had not formed the Toad Brigade.
Residing in Toad Town, the Toad Brigade were scattered across the galaxy after Bowser kidnapped Princess Peach on the Star Festival. They followed Luigi until they were eventually seperated, and then discovered by Mario. Shortly afterwards, the Toads join Mario at the Comet Observatory, where they decide to help him in his quest to gather the Grand Stars. After the Lumas help them build a spaceship, the Starshroom, the Toads form the Toad Brigade and start travelling in order to find Power Stars with Mario. They are then seen throughout several galaxies in search for the stars, and often cheer Mario on during battles. They often arrive to provide a Launch Star to Mario on their ship in order to help him progress.
The five members of the Toad Brigade each have special attributes: the leader is a red Toad who strongly resembles the normal Toad who, despite trying to come off as brave is always fleeing at the first sight of trouble, making up ridiculous excuses along the way. He can be seen as rather lazy. The purple Toad is the Mailtoad. He will give Mario letters from Peach or Luigi when received. He also enjoys snorkeling, and can often be found underwater or with a snorkel mask. The blue Toad wears glasses, and often gives Mario advice in levels. The green Toad carries a pickaxe, and often sings songs whilst digging with it. The yellow Toad is rather childish--he scares easily and can often be seen doing rather immature things such as dancing in a spotlight in Deep Dark Galaxy. He also sleeps rather often.
In the Grand Finale Galaxy they show up for a final time. Their leader reveals that because of their work in helping Mario retrieve the stars, they have been promoted to Royal Guards.