Icicle

The Icicle is one of the very first Mario series enemies. They are frozen water that falls down when Mario or Luigi is underneath it. They are extremely sharp, and kill Mario upon contact.

Description
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.

Appearances
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.

They then re-appeared in Super Mario Bros. Special, again as stationary enemies. This time they are found in castles, and are defeated by shooting a fireball at them.

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.

In Super Princess Peach they once again appeared. They appeared un-affected by the mood swings that the other enemies in the game experience, and act the same as they did in Mario Bros..

Their most current appearance was in New Super Mario Bros. Wii in world 3-3. They can come in different sizes, and can be walked upon.

Trivia

 * There is a similar enemy called the Falling Spike.