Scissor Tails are a type of t-Virus-infected arthropod bearing a resemblance to an earwig. The Scissor Tail attacks by stinging with its scissor-like tail (hence its nickname), retarding its victims with an innate and potentially lethal toxin, or by tackling and then biting the victim repeatedly, which typically induces profuse bleeding. The scissortails are very strong, especially in harder modes. According to a Newspaper article published in Raccoon City, campers encountered one that attacked their hunting dog which spent two weeks in the veterinarian's care after the attack. An Entomologist, Graham Barrows scoffed off the idea of such a creature existing following an interview after the attack. 
An Irregular mutant that seems to be a mutated earwig, it uses its newfound abilties granted to it by the T-Virus to hunt prey and induce bleeding and in some cases, poisoning. There are two kinds of of Scissor Tail and both seem to have different capabilities. The brown Scissor Tail is the largest of the two types and will induce bleeding upon unsuspecting victims. The blue Scissor Tail, while slightly smaller, will induce poison and bleeding on its victims. Both types do this either by stabbing their prey using their sharp tails or tackling and biting their prey.
Both types of Scissor Tails have mutated to the point where they have grown out of their wings. The wings, while present, are incapable of flight as they did not scale well with the Scissor Tail's mass increase and are seemingly vestigial now. When they feel threatened, they will burrow underground in an attempt to escape their attacker.
- The Scissor Tail seems to be particularly weak against weapons such as the Pesticide Spray, and especially weak against the Flame Spray and the Molotov Cocktail.
- If low on ammo, the player can use the stomp move as a means of defense. Due to being low to the ground, Scissor Tails' head is vulnerable to being stomped on by the player. In Flashback, this will not kill them as they will retreat underground after taking enough damage. However, this can prevent them from attacking as well because stomping on their heads tends to stun them. This method will usually help kill them in Elimination as well provided they don't have back up from other Scissor Tails or other enemies.
- In Elimination 2, if Flame Spray, Pesticide Spray, or Molotov Cocktail are not available, use the shotgun or the revolver (magnum handgun in harder modes) to kill these, in easy mode, the revolver ammo is plentiful. With the revolver, it may take 2 shots to kill them but usually it is 1. When using the shotgun, it will take about 4-7 rounds to take them out.
- Scissor Tails can only be encountered through either of two ways: playing "Outbreak" on Hard or Very Hard, or by playing "Flashback" and not reaching the suspension bridge before its collapse (appear on all difficulties).
- In Flashback, they will dig a hole and will retreat when they receive some high damage from the survivors.