Warp Pipe
The Warp Pipe is one of the main modes of transportation of the Mushroom Planet. Warp Pipes first appeared in the arcade game Mario Bros.. Enemies would emerge from these pipes and attack Mario and Luigi. Warp Pipes have appeared in nearly every Mario game since, although Super Mario Bros. 2 temporarily replaced them with vases. These pipes were first used for transportation in Super Mario Bros.. Some even led to underground levels and mini-levels.
Generally speaking, a Warp Pipe is a pipe that doesn't always appear to be connected to a second pipe physically, although traveling through it will transport the traveler to the other end. In many cases, Warp Pipes can be used to cross great distances (and even worlds) instantly.
The size of Warp Pipes can vary greatly. While some are too narrow for a human to enter, others are large enough for Bowser's Doomship to travel through.
During the events of Mario & Luigi: Partners in Time, special blue Warp Pipes required Mario, Luigi, Baby Mario, and Baby Luigi to stand on them in order to activate them.
In New Super Mario Bros., some warp pipes acted as mini-cannons, shooting Mario or Luigi high in the air. Mini Warp Pipes, were introduced here. Also, if Mario or Luigi use the Mega Mushroom, they can kick the pipe, move it in if it is horizontal, or Ground Pound it to make a raised pipe lower to ground level. If Mega Mario or Luigi destroys a pipe, then they cannot go down the pipe anymore.
The Nintendo Comics System comic, A Mouser in the Houser seemed to imply that the Mousers constructed the Warp Pipe system, however, if Weldenburg has a species, then it is probable that they made the Warp Pipe system as well, considering their skill.
A green pipe is an exclusive item in Animal Crossing Wild World. It has a pirahna plant inside that moves up and down. The pirahna plant will stop moving if you tap yourself while facing it.
Trivia
Warp Pipes were also featured as Easter Eggs in Advent Life.
