"What is this thing?"
This disambiguation page lists articles associated with the same title. If a link led you here, you may wish to change that link to point directly to the intended article.
Pipe refers to multiple subjects in the Metroid series. You may be looking for:
Air Hole, known as pipes in Super Metroid guidebooks
Bull, known as PIPE in the Super Metroid internal data
Half-pipe, a structure seen throughout the Prime series
Pipeline, a multiplayer map in Metroid Prime 2: Echoes
Pipework in Security Station