The Fart Gun is a weapon Dr. Nefario created after misunderstanding Gru's order for a dart gun. This weapon's gas knocks its targets out when inhaled.
It looked like a metallic rifle with a canister on top holding blue liquid and an object like a shower head attached to the end. This distributes brown gas which can travel for about a metre and a half before dissipating. When fired it sounds like someone farting. This weapon is also used as a respectful salute tool, such as the 21-fart gun salute.