The 食人魚槍 is a 困難模式, post-世紀之花 遠程武器 that fires a single, returning "piranha" projectile that costs no 彈藥. The piranha latches onto an enemy to do continuous damage while the ⚒ 使用/攻擊 button is held. If the initial target is killed and the attack button is still held, the piranha proceeds to seek out nearby enemies. It returns to the gun once no other enemies are in the vicinity; when the attack button is released; or after one minute of continuous use. The Piranha Gun is found in the 地牢's 叢林箱, which requires the 叢林鑰匙 to open.
The first enemy the piranha attaches to must be in direct line of sight. Once the initial enemy is dead, the piranha will then automatically home in on nearby enemies in range, regardless of line-of-sight, and will pass through blocks. The piranha attacks at a rate of 7.5 hits a second.
Its best 修飾語 is 虛幻.
- The piranha will not latch onto other players in PvP.
- While the ⚒ 使用/攻擊 button is held and the piranha is attacking enemies, the player can move about without worrying about keeping aim.
- The piranha can damage enemies other than the one it is currently attacking if it touches them.
- The Piranha Gun does not receive any particular bonus from any of the three 蘑菇礦盔甲 helmets (though it does benefit from the Shroomite armor set bonus).
- The Piranha Gun does approximately 15,000 total damage over the course of one minute, if it is held that long.
- The piranha travels slower in water, like other projectiles (despite being a fish).
- The piranha's damage and critical strike chance is determined at launch, and remains in effect until it returns to the gun. Example: If a player gets the damage and critical chance boost from fully-stealthed Shroomite armor, then fires the piranha, the piranha will continue dealing boosted damage, at the elevated critical rate, even if the player loses stealth by moving around.
- The Piranha Gun is great for eliminating swarms of enemies as you can hide behind walls while it jumps between enemies in a wide open space. It is especially good for eliminating 聖騎士s and teleporting enemies, since the piranha will lock onto and follow the target with each teleport.
- Its high attack rate, ability to remain on top of a target, and weak knockback, combine to slow or stun-lock many enemies. Certain enemies and bosses, or boss segments (like 石巨人's fists), cannot attack or fire while being damaged; thus, the Piranha Gun prevents them from attacking. Another example is the 聖騎士, against whom the Piranha Gun is best when paired with 翅膀 or other flight accessories that allow you to dodge around while the Paladin is worn down.
- Can be used to constantly damage Bosses without having to focus on aiming or going in close for melee attacks. This can allow the user to focus on dodging and hold out for any 減益s to clear, such as 藥水疾病.
- Can even be effective against 地牢守衛s because of its ability to cause continous damage while following its target.
- 188.8.131.52：Damage increased from 33 to 38.
- 1.2.3：Fixed bug where piranha gun would chase invincible enemies (blazing wheels and dungeon flails).
- 184.108.40.206：Does more hits per second.
- 220.127.116.11：Damage slightly increased.