In the tradition of Friday the Thirteenth’s Jason Vorhees, the murderous fiend is a template that can be added to any normal human to turn him into a virtually unstoppable killing machine. The murderous psychopath is a force of nature. He absorbs tremendous amount of punishment and keeps coming back for more. Worst of all, he tends to show up at the worst moment possible. Run all you want, he’s always right behind you.

In Call of Cthulhu, such a figure can quickly devolve into self-parody. After all, slasher movie tropes are hoary enough that films such as Scream can build entire film franchise out of poking fun at them. The murderous psychopath is a dangerous tool that cultists can dispatch to defeat the investigators. Worse, he may have once been a valued ally whose sanity has been blasted away by exposure to alien entities, transforming him into a murderous fiend. The characters should never directly confront him until their decisive showdown with him. They come across the remains of his victims, find evidence of his activities, but he remains a shadowy, menacing figure. Make a point to avoid the cheesy boilerplate trotted out by slasher films: cars that never seem to start when the murderer is about, investigators who suddenly trip on their own feet as the slasher chases them, and so on. Call of Cthulhu demands much subtler horror than that.

Instead, the murderous psychopath lurks behind the facade of the normal. He may seem a little off-kilter, but not enough for him to qualify as a killer. Ideally, the characters find evidence of his actions while interacting with him socially. Such a quick turn can enforce the subtle horror of CoC and challenge the players’ investigative and deductive skills. Only when the characters directly confront him does his ability to relentlessly stalk his victims become apparent. Think along the lines of movies such as Texas Chainsaw Massacre and HPL stories such as The Picture in the House.

"Murderous fiend" is a template that can be applied to any human whose sanity has dropped to —10. For all practical purposes, a murderous fiend has no sanity score and never makes checks against it. A murderous fiend’s creature type becomes monstrous humanoid. Apply the following changes to the character:

Hit Dice: Increase to d8.

Attacks: The murderous fiend replaces his old base attack bonus with one equal to his total hit dice. He also gains a slam attack in place of his unarmed strike.

Damage: The murderous fiend’s slam attack deals damage according to its size. Tiny fiends deal 1d3 damage, Small ones 1d4, Medium-size 1d6, Large 1d8, Huge 2d6, Gargantuan 2d8, and Colossal 4d6.

Special Attacks: The murderous fiend strikes with horrifying effectiveness. He gains proficiency with all melee weapons, increases the threat range of any melee weapon he uses by 1, and boosts a melee weapon’s critical multiplier by 1. In addition, the murderous fiend automatically confirms any critical threats he scores in melee combat.

Special Qualities: The murderous fiend gains damage reduction 10/+1. He absorbs physical attacks with ease and is incredibly difficult to put down. In addition, the fiend’s twisted insights allow him to expertly conceal his involvement in any crime. Increase the Search or Spot DCs to find clues at the scenes of his crimes by +5. The fiend’s peculiar madness also makes it easy for him to lie to others about his involvement in his slayings. He gains a +5 competence bonus to all Bluff checks. Characters using Sense Motive against him tend to read him as a guileless, if perhaps eccentric, innocent. Finally, the fiend’s twisted mind is proof against attempts to influence it. He is immune to all mind-affecting spells and abilities.

Saves: The murderous fiend has a preternatural ability to avoid danger. He gains a +2 bonus to all Fortitude and Reflex saves.

Abilities: The fiend gains a +4 bonus to Strength, Constitution, and Wisdom.

CR: As base creature +2.

Inspired by the rather amusing mid-80’s horror film Re-Animator, which was in turn inspired by the HP Lovecraft story "Herbert West — Reanimator", this template that may be applied to any animal or humanoid that died and has been exposed to the loathsome revivifying process developed by Dr. Herbert West. West’s process requires a freshly dead body that has not been preserved in any manner. Furthermore, all its vital organs must be intact. However, once a corpse is reanimated it attains tremendous strength, durability, and endurance.

"Reanimated" is a template that can be applied to any human or animal. The creature’s type changes to undead. The creature must be dead, its corpse intact, and injected with the revivifying fluid developed by Herbert West. It retains its memories and acquires a tremendous drive to stalk and kill those responsible for its undead status. Once reanimated, a creature’s statistics are modified as follows. Unless otherwise noted, it retains its original class levels, spells, skills, feats, and other abilities.

Hit Dice: Increase to d12.

Armor Class: The creature gains a +2 natural bonus to AC.

Attacks: The creature gains a slam attack using its original base attack bonus. It keeps any natural attacks it had in life, such as a bite or claw.

Damage: The reanimated’s slam attack deals damage according to its size. Tiny reanimated deal 1d3 damage, Small ones 1d4, Medium-size 1d6, Large 1d8, Huge 2d6, Gargantuan 2d8, and Colossal 4d6.

Special Qualities: Damage reduction 5/+1, darkvision 60 ft., undead qualities, conceal state, track creator, we are legion.

Conceal State (Ex): The reanimated may disguise its horrific state by wearing bulky clothes and making an effort to blend in with its surroundings. At first glance, a reanimated without obvious wounds simply appears to be a hulking, shuffling brute. As a body must be relatively intact to undergo West’s process, most reanimated appear normal at a casual glance. A reanimated may make a Disguise check to pass escape notice by the living.

Track Creator (Su): The reanimated has a constant sense of the location of its creator relative to its own. Though the creature does not necessarily know the exact location of its creator, it does know the general direction and distance it must travel to find him. A reanimated automatically recognizes the person or persons responsible for its undead state on sight. The reanimated live in a constant state of pain and seek to avenge themselves against those responsible for it.

We Are Legion (Ex): All of the creatures reanimated by a particular researcher share a common bond. They eagerly work together to destroy the one responsible for their creation and have an intuitive link they use to sense one another and form an alliance.

Abilities: The reanimated gains a +8 bonus to Strength, a —2 penalty to Dexterity, and a —4 penalty to Intelligence and Charisma. As undead creatures, the reanimated do not have Constitution scores. If these changes drop an ability score below the minimum needed for a feat or other feature, the reanimated loses the use of those features. For example, a reanimated that had the Dodge feat in life may no longer use it if his Dexterity drops below 13 as a result of applying this template.

Skills: A reanimated creature gains 5 ranks in Climb, Jump, and Listen.

Feats: The reanimated gains the Toughness feat.

CR: As base creature +1.

Climate/Terrain: Any.

Sanity Loss: 1/1d6 or as base creature, whichever is higher.

These battered, yellowed notebooks’ mundane appearance contrasts with the remarkably brilliant yet horrifying information they contain. In the course of Herbert West’s studies, he unearthed ghastly secrets of the divide between life and death that allowed him to formulate a chemical that can bring a creature back from the dead. The body to be revived must be in good condition, complete with its vital organs. It may not have been embalmed or otherwise prepared for burial.

Herbert West never succeeded in reviving a person into a sane, fully thinking state. Instead, those he animated came back as murderous beasts who seek the death and dismemberment of the one responsible for their state. Unfortunately, West insisted that he merely needed a fresh enough body to successfully revive the dead. His notes make passing references to the horrors he unleash, but primarily focus on the potential his process holds for restoring the dead to life.

Herbert West’s Research Notes: In English, by Dr. Herbert West, A. D. 1920. These three battered notebooks are written in a flowing, confident script. They summarize Herbert West’s research into revivifying the dead but, unluckily for any who read them, make only passing mention of the difficulties West faced. Examination Period: 2d4 weeks (DC 25). Contains no spells. Sanity Loss: 0 initial, 1d4 upon completion. Cthulhu Mythos: +0 ranks. Special: Anyone who reads and successfully studies this work gains the ability to produce the formula used by Dr. West to re-animate the dead. Each dose costs $25 (1920’s campaigns) or $200 (modern campaigns) to produce, one week of work, and a Knowledge (chemistry) check of DC 25. In order to fully comprehend the process outlined in this book, the reader must have at least 6 ranks in Heal or Knowledge (medicine). Upon completing an examination of this book, the reader must make an Intelligence check (DC 20) to ascertain the true results of West’s work.