Insects are creepy.
But what's particularly creepy is having one clambering across your back, where you may not even know it's there.
A Back Arach is often used to show how scarily exotic and potentially deadly to Western audiences a locale is. Someone will ask someone else if there's something on their back, only to turn around and have one or more giant insects or spiders there.
Sometimes the second person will casually say, 'turn around', show the audience the spiders, then brush them off.
Film - Animated
Film - Live-Action
- Blu in Rio manages to get a spider on his back, which Jewel brushes off, pretending it's a leaf so he doesn't get even more freaked out at the jungle.
- Alex in Madagascar gets a good-sized spider on his back which freaks him out.
- Raiders of the Lost Ark. While Indy and Satipo are exploring the tunnel Indy gestures to Satipo to turn around. When Satipo does so, it's revealed that his back is covered with tarantulas. Indy then brushes them off with his whip.
- Happens to Will Ferrell's character in Land of the Lost with a giant blood sucking tic.
- Predator: Mac (seemingly) stabs Dillon in the back. It's revealed that he was actually aiming at a scorpion that was crawling on Dillon's back.
- In Galaxy of Terror, one crew member is stalked by a big spider-like creature in the wrecked ship, and just when he thinks it's gone for good, we see its clawed legs rising behind his back, killing him.
- Kids rhyme:
Ten knives in your back, blood running down,
ten spiders crawling up, snakes all around.
Cool Breeze, tight squeeze; now you've got
- The stock image of the Harvester race in Master of Orion III inverts this... sort of. The Harvester itself is a large bug-like creature, with a lifeless-looking humanoid pictured on its back—but that is apparently how the Harvester feeds on the humanoid, or whatever other type of sentient creature it's currently feeding on.
- In World of Warcraft there's the Sabotage debuff applied by some huge insectoid enemies attacking your character from behind. The buff description? "Don't look now there's a mantid on your back!"
- South Park. This happens in the episode "Rainforest Schmainforest," proving Cartman is right about the rain forest being a scary, deadly place. This is one in a series of events which leads the rainforest-loving Miss Stevens (voiced by Jennifer Aniston) to decide that she hates the rain forest instead.
- A Crying Wolf short in Dexter's Laboratory involved Deedee annoying Dexter by constantly asking him "Dexter, what's that?!" and pointing dramatically. Dexter would look each time and see nothing, getting more and more frustrated. The third time, Deedee actually gets worried and says it again. Cut to Dexter smugly closing his eyes and saying "Oh no, I'm not going to fall for that again" while a gigantic mutant beetle crawls on his face.