Toad (named as the Toad Brigade Captain) is the self-proclaimed leader of the Toad Brigade. He often wears a flashbulb helmet and a large backpack. While he makes every effort to construe himself as brave, he's always running away at the first sight of trouble, making preposterous excuses whilst he is at it to the point of which one of the missions involves rescuing him.
The Purple Toad is the Mailtoad, who forks over letters from Princess Peach and Luigi. When he is not delivering anything, he is snorkeling.
The Blue Toad wears glasses, and gives advice to Mario in levels when it is desired.
The Green Toad carries a pickaxe, which he uses to dig, and while he's busy digging he's also singing to himself. In Super Mario Galaxy 2 he is the Banktoad that allows the player to give Star Bits to other players with save files, or just hold them for safekeeping.
The Yellow Toad spins around in circles or sleeps. He also sleeps in Super Mario Galaxy 2.