Column (Super Mario World)
From the Super Mario Wiki
Columns are large, indestructible pillars found in Super Mario World. These obstacles appear mostly in fortresses, towers, and castles, usually hidden in the floor, ceiling, or also in walls. They move slowly for some seconds, revealing themselves, before suddenly smashing almost anything on their way. After some seconds later, Columns move slowly back. If the player reaches the door at the end of rooms with columns, but doesn't enter it, the nearby column will appear to be cut off by the wall.
A column appears in the first volume in the Super Mario World arc of the Kodansha-published Mario manga. While Mario and Luigi are walking through Iggy Koopa's castle in an open room, Mario looks up and tries warning Luigi of a falling column, but it crushes Luigi. Mario then has to toss a crushed Luigi through a window.