Spider-tailed horned vipers have a unique adaptation in their tail shape that is most helpful in attracting potential prey. The tail of the spider-tailed horned viper resembles a spider, which lures birds closer as they mistake it for prey. When a bird comes close to investigate the "spider," the viper strikes and captures its prey. This tail adaptation is a specialized feature that enhances the viper's hunting success by attracting unsuspecting prey within striking range.
In contrast, the pattern of scales, shape of pupils, and size of fangs are adaptations that serve different purposes in the viper's survival but are not directly related to attracting potential prey. The pattern of scales and shape of pupils may help with camouflage and hunting, while the size of fangs is crucial for delivering venom to subdue prey once caught.
Therefore, among the options provided, the shape of the tail stands out as the adaptation most helpful in attracting potential prey due to its specific mimicry strategy that capitalizes on the curiosity of birds, leading them closer to the viper for an effective strike.
