Ice Ball
An Ice Ball is a ball of ice that can be used as a projectile, and is capable of freezing enemies. Mario can gain the ability to shoot Ice Balls by using either an Ice Flower or a Penguin Suit, which will transform him into Ice Mario or Penguin Mario respectively. Ice Bros. and Venus Ice Traps are also capable of shooting Ice Balls. When shot, an Ice Ball will bounce along the ground briefly, then shatter. Ice Balls can be viewed as a parallel to Fireballs.
History
Mario & Luigi: Partners in Time
Ice Balls first appear in Mario & Luigi: Partners in Time, where Mario, Luigi, Baby Mario and Baby Luigi can shoot them at enemies when they use an Ice Flower.
New Super Mario Bros. Wii
Ice Balls would go on to make their first platformer appearance in New Super Mario Bros. Wii. Mario, Luigi, Blue Toad and Yellow Toad can attack with them if they manage to become Ice Mario, Ice Luigi, Ice Blue Toad or Ice Yellow Toad by use of an Ice Flower, or Penguin Mario, Penguin Luigi, Penguin Blue Toad or Penguin Yellow Toad by using a Penguin Suit. Many enemies, upon being hit with an Ice Ball, will become frozen in a block of solid ice. It can freeze a multitude of enemies, including fireproof ones such as Buzzy Beetles and Dry Bones that cannot be harmed with Fireballs. A frozen enemy, if it is ground-based and not overly large, can then be picked up and thrown, much like a Shell, taking out any enemies in its path. If left alone, a frozen enemy will break out of its ice block after a brief period of time. A frozen enemy can be destroyed by having it collide into any surface, Ground Pounding it, jumping at it from beneath, tossing a Shell or another frozen enemy at it, or touching it as Invincible Mario. If a frozen enemy collides into a playable character, the enemy will be destroyed. The character will get knocked back a bit, but will not take damage. If a frozen enemy is defeated, it will drop a Coin.
If an Ice Ball hits an airborne enemy, such as a Koopa Paratroopa or Bullet Bill, the frozen enemy will remain in mid-air for several seconds, before falling to the ground. During this brief time, the block of ice can be used as a stepping stone.
If an Ice Ball hits an aquatic enemy that does not resist it, it will float up towards the surface and never thaw out.
Certain enemies, particularly larger ones such as Super Piranha Plants and Thwomps are impervious to being frozen; if they are hit by an Ice Ball, they will either freeze up and thaw out immediately, or will simply cause any Ice Balls that hit them to shatter upon contact.
Ice Balls can also be used to dispel the magical projectiles that are fired by Larry, Roy, Iggy, Morton Ludwig von Koopa and Kamek, as well as Bowser and Bowser Jr.'s Fireball attacks. Additionally, Ice Balls will destroy Podoboos upon contact.
It is possible for a Yoshi to grab an Ice Ball with its tongue and hold it in its mouth. If the Yoshi spits out the Ice Ball, it will travel forward indefinately, freezing any enemies in its path.
Ice Bros. attack using Ice Balls, which will not only damage Mario if they hit him, but will temporarily freeze him within a block of ice.
Paper Mario: Sticker Star
Ice Flower Stickers appear in Paper Mario: Sticker Star, granting Mario the ability to shoot Ice Balls at enemies. Ice Bros. also attack by shooting Ice Balls.
New Super Mario Bros. U
As it plays similarly to New Super Mario Bros. Wii, Ice Balls in New Super Mario Bros. U function essentially the same way as they did previously. Venus Ice Traps also attack by shooting Ice Balls. However, much like the ones that a Yoshi can spit out, these Ice Balls will travel forward indefinately, and are capable of freezing not only playable characters, but fellow enemies as well.