Blow Gun

A tube used to shoot darts at targets. Often used by tribesmen. Expect poison and tranquillizer darts.

It's near-silence makes it an ideal exotic weapon for an assassin. It's surprisingly common for the user to accidentally inhale the dart. Another regular gag is for the target to grab the end of the gun and blow the dart back.

Anime and Manga

 * Used by a guy in Hunter X Hunter, who uses it to shoot a paralyzing dart at Gon.
 * Ranma ½ uses one to shoot down the Principal's hot air balloon in the manga

Comic Books

 * A group of onetime villains in Spider-Man comic (four criminals who learned to copy Vulture's wings) used those. The curare was fatal for humans -- Spider Man was too tough to die, but would get stiffer with every dart and actually got close to succumbing. The next issue, he had to save their lives when the real Vulture came to town.
 * In one Batman storyline during the Zero Hour series, The Joker frames Batman for the Penguin's murder by having a henchman shoot a poison dart this way, thus making it appear as if Batman knocked Penguin off a side railing with his Batarang and made the villain fall to his death.

Film

 * Used in Hudson Hawk (by CIA agents, who should logically have something better), with explicit mention of curare, which is treated as a temporary paralyser. Because it was improperly prepared, the victims recover sooner than anticipated.
 * Used in Ace Ventura: When Nature Calls. Ace is shot with dozens of little darts (with hilarious effects) before he passes out.
 * Used in Raiders of the Lost Ark in the opening sequence.
 * Also seen in Indiana Jones and the Kingdom of the Crystal Skull in the tomb sequence. Indy does the "blow the dart back" trick.
 * In Young Sherlock Holmes, an assassin uses a blowgun to shoot darts tipped with a hallucinogenic drug.
 * The natives in Aguirre, the Wrath of God keep sniping at the conquistadors on the raft with these.
 * Tim Allen's character in Jungle 2 Jungle contrives to shoot himself in the leg with semi-paralytic darts not once but twice. Once was mildly amusing, twice makes you despair for the writers.

Literature

 * In The Colour of Magic, the leader of the Assassin Guild use a blowgun as his weapon.
 * In The Sign of the Four, Tonga uses poison blow darts.
 * In one Forgotten Realms novel, the pirate hunter Captain Deudermont is darted by a thug who wanted to claim the black-market bounty on him. Apparently, his darts are made from cat claws (don't ask how those could be used as darts) and no other ammunition is compatible with his blowgun.
 * In Midworld and its sequel, human hunters on the green world use rifle-like blow guns called "snufflers", modeled on distant memories of their colonial ancestors' firearms. They're powered by tank seeds, which contain air bladders that burst when punctured, propelling their toxic-thorn projectiles with great force.

Live Action TV

 * Myth Busters made these in the ninja special.
 * Parodied in a TV sketch of the comic trio Aldo, Giovanni and Giacomo, where the blowgun is used to anesthetize a patient.
 * Doctor Who: The Doctor uses one against the assassin in "The Deadly Assassin".

Tabletop Games

 * Warhammer Fantasy has these as a Wargear option for Skinks, and a Huge version for mounting on dinosaurs.
 * Dungeons and Dragons: The Unearthed Arcana (1985) supplement introduced the blowgun (which was 4-7 feet long) as an available weapon. The needle did only one Hit Point of damage, and was therefore only effective if poisoned.

Video Games

 * Little Big Adventure: Twinsen, the player character, uses one in the second installment.
 * Donkey Kong 64: Lanky's Grape Blowgun
 * In the second chapter of Eternal Darkness, you receive these. It poisons enemies but does very little damage either way and has limited ammo. If you use it to Cherry Tapping some zombies to death in order to save a particular NPC, however, you can get your sword (which just broke) repaired and then upgrade it to Dual-Wielding with what would have otherwise been the replacement.
 * In Civilization Revolution, one of the barbarian tribes you can encounter has their spokesman threaten you with a blow gun.
 * The Apple II game Aztec revolved around robbing an Mayincatec tomb. In the deepest levels there were 8-bit natives armed with blow guns. The stun effect was deadly: if the native didn't get the player, the wildlife probably would.
 * Teemo from League of Legends uses this as his trademark weapon in order to pump his enemies full of poison.
 * Diablo II has pygmy enemies that uses blow darts to attack.
 * You can find blowguns in some chests near the surface of Terraria. While getting ammunition for it is a cinch (it uses seeds that you collect by cutting grass), the weapon is far outclassed by most other ranged weapons, at least one of which you should have at that point.

Web Original

 * The Cinema Snob has this in Kickassia (mostly because Brad wanted to stand out with everybody wielding fake weapons, so his weapon was a packet of straws he bought in a gas station.
 * And he inhales one of the darts.

Webcomics

 * In Strays, Feral starts putting one together, before the Tagalong Kid botches his assassination job.

Western Animation

 * In a Looney Tunes short, a Wacky Native tries to use a blowgun on Bugs Bunny, but Bugs blows in the other end just before the native does, so it ends up going down the native's throat. The same gag was also used against prehistoric Elmer Fudd.
 * In the Jonny Quest episode "The Deadly Doll", the villain Korbay uses a blowgun to fire darts that have a poison that causes its victims to enter a coma.
 * In a Happy Tree Friends short, Lumpy attempts to sedate a animal mauling one of the "children", but accidentally sucks the dart in when taking his breath.