From the Super Mario Wiki
The title of this article is conjectural; an official name for the article's subject has not been found, so it has been given a fitting title by editors. If an official name appears, it is requested that the article be moved to the correct name.
Beak Pillars are thin, short , smooth-sided wooden pillars that resemble pencils. They come down from the ceiling or up from the floor. Most don't retract all the way, leaving their deadly point exposed. They are found in Super Mario World in the Chocolate Fortress and Larry's Castle. They are indestructible obstacles, but can be touched from the side unlike a Skewer, which, unlike the wooden stakes, have spike-studded sides.