Toad

Toad is Princess Peach's attendant. His Japanese name is Kinopio. He has been a protector of the Mushroom Kingdom and is first playable in Super Mario Bros. 2. His species is basically him in different kind of colors (kind of like Yoshi of the Yoshi species.) He is a main protagonist and has the role of supporting Mario and co. on the travels, adventures, and journeys.He is heroic and stops Wario and his evil plans and saves the Mushroom Kingdom in the game Wario Woods. Toad has been seen in Toad Houses as the main host.

Super Mario Bros.
Toad first appears in Super Mario Bros. as a Mushroom Retainer with 7 other Mushroom Retainers. They have been captured by Bowser and False Bowsers. After Mario saves one of them and defeat the False Bowsers, they say the famous saying "Thank You, Mario. But, our princess is in another castle."

Super Mario Bros.:The Lost Levels
Toad and the other Mushroom Retainers appear in SMB:TLL like in SMB but, this time have a more major role in the game. More Retainers are needed to be rescued to stop Bowser's forces which is why there are an increased number of levels in this game than the previous game. In addition to Bowser's stronger forces, he kidnapped Peach again and has brought her to the new Mushroom lands. And it's up to Mario or Luigi to save her once more with the Mushroom Retainers.