The Icicle is basically a sharp, white triangle that dangles from the ceiling. They fall when Mario is located directly underneath them, and if the player does not move they will instantly kill Mario upon contact. This is their only attack, however, in all of the games they appear in.
The Icicle has appeared in, to date, 6 games not counting remakes or re-releases. Their first game was Mario Bros., where they appeared later on in the game. At round 16, the Icicles first appear. They are the fifth enemy to appear in the game, and the only enemy that is stationary. They can only be killed when spawning or by dodging them as they fall, making them the most difficult enemies in the game to defeat.
In Super Mario World 2: Yoshi's Island they appeared again. They used the same methods of attack as the other games, but could be knocked off of the ceiling by an egg.
In Wario Land: Shake It they appeared in one of the levels. This time they are much bigger than they were in previous games, and could be stood upon once knocked down.
They also appear in New Super Mario Bros. U and act as they did in the previous game, New Super Mario Bros. Wii.
- There is a similar enemy called the Falling Spike.