Small pipes[1][2] are tiny Warp Pipes that require the player to be tiny in order to enter. Half the size of a regular Warp Pipe, they made their debut in Super Mario Bros. 3.
Small pipes first appear in Super Mario Bros. 3, in World 2-1. They appear with a purple coloration and do not serve any purpose other than being decorative structures. Small pipes also appear in World 7, where they are green and may have Munchers pop out of them.
Small pipes make their first functional appearance in New Super Mario Bros.. They serve the same purpose as Warp Pipes, but can only be used by players in their Mini form. Star Coins are often hidden inside rooms that can only be accessed via these pipes. Usually, they also contain shortcut rooms with coins that can be used to skip some parts of the level.
Small pipes reappear in Super Mario Maker 2 in the Super Mario Bros. 3 game style as the ground tiles in the forest and desert themes, being green and purple respectively.
Small pipes appear in Super Paper Mario. The player has to use Dottie to shrink their character so they can enter them, similar to the use of Mini Mushrooms in the New Super Mario Bros. games.
Mario & Luigi: Bowser's Inside Story / Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey[edit]
In New Super Mario Bros. Wii and all subsequent New Super Mario Bros. games, when a mini character enters a small pipe, they exit out of a normal-sized one. This is likely due to the fact that other players not in the correct form can exit the same pipe in multiplayer.