Toads are a species commonly found in the Mushroom Kingdom. They are slightly smaller than Mario, and look human except for the mushrooms on their heads.
A Toad was found at the end of each of the castles guarded by a fake Bowser. When Mario reached the Toad, he would always say "Thank you Mario. But our princess is in another castle!"
A Toad is one of four playable characters, which the player can select at the beginning of each stage. Toad can't jump as high as the others, but can pick up items quickly.
Toad traveled with Mario, Luigi, and Princess Peach through the world of Subcon to defeat the evil Wart and rescue the people of Subcon. They eventually succeeded, but then Mario woke up to find that the whole game was a dream. It is unknown if Toad, Peach, or Luigi had the same dream as well.
Several Toads set up houses throughout the various worlds. Some have Mario pick from three chests for an item, and some have him play a minigame for extra lives.
The Toads were trapped in the walls of Peach's Castle when Bowser attacked. They were able to talk to Mario, sometimes giving him hints, and on rare occasion a Toad would give him a Star. They were released from their imprisonment when Mario defeated Bowser.
Toads could be found inside Luigi's Mansion looking for Mario. They would always give Luigi the option to save when he talked to them.
Toads are commonly found in this game, mostly in Rogueport. Notable Toads are Zess T., Jolene, Prince Mush, the Conductor, the Engineer, Toodles, the Waitress, Zip Toad, and Ghost T. Toads can also be seen in the audience sometimes.
There are several Toads in a town called Little Fungitown in the Beanbean Kingdom. Also, Toads appear at the beginning at Peach's Castle, and the player controls a Toad for a brief moment near the beginning.
Toads are commonly found in Peach's Castle. However, many of them were abducted by the Shroobs and had all their vim sucked out of the mushrooms on their heads to be used as fuel for the Shroob UFOs. Once they were no longer of any use, the Shroobs would turn them into mushrooms. They were restored with baby tears after Elder Princess Shroob was defeated. Notable Toads, besides Toadsworth, are Toadiko and Toadbert.
When Fawful made Bowser eat a Vacuum Shroom, he inhaled several Toads, including Toadsworth and Toadbert. Most of the Toads could be seen inside the Toad Square area, setting up shops for the Mario Bros. They were all forced out of Bowser when Fawful was destroyed, reversing the effects of the Vacuum Shroom.
Bowser kidnapped 126 Toads, keeping three each in a stage of each world (with five stages each), and one more being held prisoner by a boss. One Toad each was guarded by Petey Piranha, Hoo, King Boo, Wiggler, Gooper Blooper, and Blizzaurus. Giant Kamek was holding Luigi prisoner. It was only after rescuing all the Toads that Peach could get to Bowser and defeat him.
Five Toads called the Toad Bridade appeared to help Mario get Power Stars back and defeat Bowser.
The Toad Brigade also appears in this game.
Two Toads, a yellow Toad and a blue Toad, are playable characters, controllable by the second, third, or fourth players. Also, several Toads are held prisoner by enemies on the map, and give Mario items when released. More Toads are hidden inside blocks across the levels. If Mario saves the Toad, he will give Mario an extra life or open up a Toad House at the beginning, however, the Toad can be killed during the level and never return.
A Toad appeared once at the beginning to tell Mario and Luigi that Peach was kidnapped. They did not make any reappearance afterward, as everything after Bowser's Castle takes place in dimensions separate from the Mushroom Kingdom.