Ice Rod

The Ice Rod is a Hardmode magic weapon that auto-fires shards of ice. The weapon is unique, in that if the point clicked is free of any blocks or placed background items, a solid 1x1 "ice block" (translucent, but not slippery) is formed in midair, at the point clicked, which lasts for about six seconds before shattering. Ice blocks can create temporary platforms for standing or grappling, and also cast a dim, flickering light. Each shot consumes 7 Mana. The Ice Rod is available from the Wizard for 1 Platinum.

The point clicked must be unoccupied in order to form an ice block. If the space clicked is occupied, either by blocks or background objects, the shard acts as an ordinary projectile, continuing until it hits an enemy or other foreground object, where it shatters. Clicking an ice block to fire again will cause your next shard to pass through the ice block, which creates unique shielding possibilities during combat, as while you can fire through your ice shield, enemies can not move or fire through them (with the exception of Worms, Casters, Bosses, and other enemies that can attack through blocks).

Upon shattering, ice blocks release illuminated sparks that travel down through blocks all the way to the bottom of the screen, making the Ice Rod very useful for discovering ores and caves.

Trivia

 * This item may be a reference to The Legend of Zelda: A Link to the Past, where you can get a weapon with the same name.
 * Before 1.1 release Ice Rod was shown in a dev blog post and the 1.1 trailer.