A sourcebook for The Yellow King Roleplaying Game

The Carcosans Are Coming

Have your Yellow King Roleplaying Game players grown complacent battling gargoyles, vampires, and riot dogs? Do you have a reality horror mystery crying out for a fresh and bizarre villain to drive it?

The Yellow King Bestiary solves your problems by helping you create some for your Belle Époque art students, Continental War soldiers, alternate reality ex-insurgents, and ordinary people trapped in unraveling normalcy.

From alien parasites to warped human conspirators, from hungry buildings to incarnations of drought, from gods torn from the pages of myth to war machines that hunt in wolf-like packs, The Yellow King Bestiary presents 86 new Foes to mystify, haunt and menace your investigators.

Throw icewater into your player’s veins with 100 brand new Shock and Injury cards. The book also includes all the preexisting cards you need to run these adversaries and beasties without reaching for any other volume.

Foe descriptions key themselves to one of the game’s four twisty sequences. Each entry also includes hooks inspiring you to repurpose the Foe in the other three settings.

With this book in your feverish hands, the investigators can:

  • Tremble in aesthetic unease when confronted by the Living Portrait!
  • Flee the blazing weapons fire of the Angel of Mons!
  • Shudder at the razor teeth of the hinge-jawed Flip-tops!
  • Open their apps to fall into the validating, concerned clutches of the Chirpers!
  • And much much more…

Whatever hole opens up in your reality today, an antagonist from The Yellow King Bestiary is ready to slither out of it, through your mind and into your heart.

Authors: John Harness, Kira Magrann, Sarah Saltiel, and Monica Valentinelli, with Daniel Kwan

Project Status: in copy-editing

Release Date: TBA

TimeWatch and Swords of the Serpentine designer Kevin Kulp picks a favorite monster that strongly resembles him, then throws us off the scent with another requiring us to read between the lines.


TimeWatch is a time-travel adventure RPG where brave agents of TimeWatch defend the timestream from radioactive cockroaches, psychic velociraptors, and human meddlers. Go back in time to help yourself in a fight, thwart your foes by targeting their ancestors, or gain a vital clue by checking out a scroll from the Library of Alexandria. But watch out for paradoxes that may erase you from existence… or worse.. Purchase TimeWatch in print and PDF at the Pelgrane Shop.

When choosing his favorite monster, Robin looked to three criteria: ickiness, impersonality, and versatility.


GUMSHOE is the groundbreaking investigative roleplaying system by Robin D. Laws that shifts the focus of play away from finding clues (or worse, not finding them), and toward interpreting clues, solving mysteries and moving the action forward. GUMSHOE powers many Pelgrane Press games, including The Yellow King Roleplaying Game, Trail of Cthulhu, Night’s Black Agents, Esoterrorists, Ashen Stars, and Mutant City Blues. Learn more about how to run GUMSHOE games, and download the GUMSHOE System Reference Document to make your own GUMSHOE products under the Creative Commons 3.0 Attribution Unported License.

When Ken selects his favorite monster, he goes for creepy crawlies with a viewpoint. Plus special bonus F20 monster!


Trail of Cthulhu is an award-winning 1930s horror roleplaying game by Kenneth Hite, produced under license from Chaosium. Whether you’re playing in two-fisted Pulp mode or sanity-shredding Purist mode, its GUMSHOE system enables taut, thrilling investigative adventures where the challenge is in interpreting clues, not finding them. Purchase Trail of Cthulhu and its many supplements and adventures in the Pelgrane Shop.

When asked to name his favorite monster, Noah selects a deep cut that cuts deep.


The Fall of DELTA GREEN adapts DELTA GREEN: THE ROLE-PLAYING GAME to the GUMSHOE investigative roleplaying system, opening the files on a lost decade of anti-Mythos operations: the 1960s. Players take on the role of DELTA GREEN operatives, assets, and friendlies. Hunt Deep Ones beneath the Atlantic, shut down dangerous artists in San Francisco, and delve into the heart of Vietnam’s darkness. Purchase The Fall of DELTA GREEN in print and PDF at the Pelgrane Shop.

When Ruth Tillman picked ghouls, she scooped Gareth Ryder-Hanrahan for his choice of Favorite Monster. Surely that won’t happen a second time.


Trail of Cthulhu is an award-winning 1930s horror roleplaying game by Kenneth Hite, produced under license from Chaosium. Whether you’re playing in two-fisted Pulp mode or sanity-shredding Purist mode, its GUMSHOE system enables taut, thrilling investigative adventures where the challenge is in interpreting clues, not finding them. Purchase Trail of Cthulhu and its many supplements and adventures in the Pelgrane Shop.

When other members of the team thought of their favorite monsters, they picked the ones they wanted their characters to battle, or to unleash on their players. Head Pelgrane Cat Tobin picked the one she wanted to be.


Trail of Cthulhu is an award-winning 1930s horror roleplaying game by Kenneth Hite, produced under license from Chaosium. Whether you’re playing in two-fisted Pulp mode or sanity-shredding Purist mode, its GUMSHOE system enables taut, thrilling investigative adventures where the challenge is in interpreting clues, not finding them. Purchase Trail of Cthulhu and its many supplements and adventures in the Pelgrane Shop.

When the Pelgranes started talking about their favorite monsters, @brightneedle jumped in to put dibs on her subterranean, misunderstood besties.


Trail of Cthulhu is an award-winning 1930s horror roleplaying game by Kenneth Hite, produced under license from Chaosium. Whether you’re playing in two-fisted Pulp mode or sanity-shredding Purist mode, its GUMSHOE system enables taut, thrilling investigative adventures where the challenge is in interpreting clues, not finding them. Purchase Trail of Cthulhu and its many supplements and adventures in the Pelgrane Shop.

13th Age designer Rob Heinsoo takes you on a tour of the monsters he has known and loved throughout his gaming career, before finally naming on a particularly powerful and clever adversary as his favorite monster.


13th Age combines the best parts of traditional d20-rolling fantasy gaming with new story-focused rules, designed so you can run the kind of game you most want to play with your group. Created by Rob Heinsoo and Jonathan Tweet, 13th Age gives you all the tools you need to make unique characters who are immediately embedded in the setting in important ways; quickly prepare adventures based on the PCs’ backgrounds and goals; create your own monsters; fight exciting battles; and focus on what’s always been cool and fun about fantasy adventure gaming. Purchase 13th Age in print and PDF at the Pelgrane Shop.

In a virtual version of their popular 13th Age Monster Design Workshop, Rob Heinsoo, ASH LAW and Wade Rockett explore principles of F20 monster design and, based on audience suggestions, spitball a joy-eating fungal threat.


13th Age combines the best parts of traditional d20-rolling fantasy gaming with new story-focused rules, designed so you can run the kind of game you most want to play with your group. Created by Rob Heinsoo and Jonathan Tweet, 13th Age gives you all the tools you need to make unique characters who are immediately embedded in the setting in important ways; quickly prepare adventures based on the PCs’ backgrounds and goals; create your own monsters; fight exciting battles; and focus on what’s always been cool and fun about fantasy adventure gaming. Purchase 13th Age in print and PDF at the Pelgrane Shop.

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