The spider-tailed horned viper lures prey by wiggling an arachnid-shaped growth on its tail. Scientists finally looked inside the appendage.

A number of creatures on Earth possess a sting in their tails – but there's only one animal known to science with a spider for a tail.

The natural world is full of animals that use mimicry to survive, but few examples are as unusual as the spider-tailed horned viper. Native to Iran, this elusive snake has evolved…