Pipes are a standard background element. Pipes can be used as platforms.
Pipes and Teleport Pipes are different entities in the editor.
Items can be placed in Pipes. When an item is placed in a pipe, the item will be spawned out of the pipe when Mario comes near the pipe. Only one copy of the item can exist at a time; if the item is collected or destroyed, another will be produced.
Enemies can also be placed in pipes. Stationary enemies, such as the Piranha Plant, pop out of the pipe to attack (unless Mario is on or directly next to the pope), then back in; if the enemy is defeated, it will stop appearing. Mobile enemies continually emerge from the pipe, one after another.