Toad is a single character that is actually part of an entire species, who appears in the Mario series of games. He is usually seen helping Mario in his adventures, although he sometimes does more. His first appearance was in Super Mario Bros. in 1985, where he was held captive in one of Bowser's castles and guarded by a fake Bowser.
Toad is generally seen as a happy person, without showing any kinds of anger. He can be quite cowardly at times, sometimes even abandoning his friends and fellow Toads, although he has been shown to be the exact opposite, helping out his friends and Mario.