Terraria (Wiki): Flying Knife

The Flying Knife is a type of thrown melee weapon that returns to the player after damaging an enemy (pierces nine at close range), traveling for 20 tiles away, ricocheting for one time, or hitting a solid object. If the Use/Attack button is held, the Flying Knife can be manipulated like Controlled Magic Weapons, piercing infinitely. Releasing the Use/Attack button or after continuous use for one minute will the Flying Knife return to the caster.

When normally used, the Flying Knife will emit light, making the players see a little better in the dark. It also phases through any type of block when returning to the user. The Flying Knife can also squeeze through one-block-wide gaps at the right range. When used on liquids, the Flying Knife’s travel speed and range drastically decrease.

The Flying Knife’s movement is generally erratic, especially when the cursor only stays in one place.

One can easily handle a wave of slightly strong enemies and deal decent knockback with the Flying Knife. Damaging enemies on both ends of a wall is also possible when executed at the right position and range. This unique property makes the Flying Knife pass through walls unhinged while keeping hostiles at bay.

Since the Flying Knife is a melee weapon, some accessories, all flasks, and armor can enhance its travel range, flight speed, and apply flask-related buffs.

While casting, the Flying Knife can still be controlled by players and defend themselves from enemies after getting Stoned by Medusa.

During a boss fight against the Twins, care should be practiced since one of them can start transitioning to a more dangerous phase because of the Flying Knife’s piercing capabilities. The same can be said when facing the Destroyer, but it can be remedied by strategically placing the cursor at the right position where its segmented bodies will take damage from the Flying Knife.

Generally, the Flying Knife can easily dissolve a large wave of enemies. The thrown weapon can also be used while sleeping without deactivating the 5x speed benefit from using the bed, keeping the area safe from hostiles.

The Flying Knife is best modified with Godly or Demonic, providing a wide array of stats improvement. In most cases, the Godly modifier complicates things, as the bonus knockback may bring more harm than good to the player. As a remedy, Ruthless may be helpful, reducing the knockback distance from the player’s cursor.