This is when wounds caused by an enemy's attacks, no matter how trivial, will always infect the target with The Virus, a Viral Transformation, poison, or outright kill them. This can be a bite, a scratch, ingesting or having some of their "juices" fall in an open wound, or at their most virulent simply by physical contact. Fighting these enemies usually requires distance weapons, extensive hazmat/combat armor or being extremely quick to dodge. They can still be wrestled without immediate infection, but there's the risk of a stray nibble or scratch. This trait tends to make even fragile Mooks extremely dangerous, and when part of a more dangerous creature's repertoire nearly impossible to fight. For these reasons the protagonist either starts out as or becomes The Immune (or has a huge supply of antidote at the ready). This is very often a standard part of the Zombie Apocalypse, though Our Zombies Are Different means it's not universal. Some creatures like Werewolves are only capable of this when transformed... and it assumes the victim isn't eaten first. See also Poisonous Person, who can kill or infect without the need for touching or wounding. The Plaguemaster may have this as an ability, as would their victims. Contrast Touch of Death, a martial arts technique.
- Cutter in ElfQuest becomes feverish and delirious after being bitten by a squirrel. Justified in that he was trying to save it from drowning in a slimy pool of water.
Red Queen: Just one bite, one scratch from these creatures is sufficient, and then you become one of them.
- 28 Days Later. The Rage virus can be passed on by a bite by one of the Infected or a drop of infected blood introduced into the body, e.g. in the eye or by a cut.
- With the Darkhounds in The Wheel of Time, a single drop of blood or saliva on the skin is enough to kill without magical healing.
- Cardinal in The Duchess of Malfi poisons his lover by getting her to kiss his (poisoned) Bible, in possibly the most ridiculous piece of drama ever.
- Vampires in The Strain turn anyone fed upon, and to add to the fun the parasitic worms coursing through their blood are also capable of burrowing through skin.
- River Song from Doctor Who likes poisonous/hallucinogenic lipstick. The same for John Hart from Torchwood.
- Get Smart: Doctor Yes has very long poisoned fingernails. Max tricks him into scratching himself on the face.
- On Star Trek: Deep Space Nine, the Jem'hadar make use of a weapon that prevents blood clotting in damaged tissue when it hits, so even a glancing wound will cause a victim to bleed to death.
- Hamlet: Polonius poisons Laertes' sword for a duel Laertes will fight with Hamlet, unknown to Laertes. One scratch and Hamlet will drop dead, although it's not immediate.
- In the Simpsons version of Hamlet, RosenCarl and GuilderLenny are also dosed with poison in case Hamlet touches one of them. They high five each other and collapse to the ground, dead.
- Komodo dragon saliva works this way. They just need to nibble the victim and then they will follow it, waiting for septic shock to finish the job.
Hello, Unknown Troper. You'll need to get known to lend a hand here.