Monster Blood is a thick, green slime with magical properties that appears in several Goosebumps books.

Initially, Monster Blood resembles a typical novelty "slime" toy, such as Mars Mud or Silly Putty, and comes in a small metal can. It can glow in the dark and will bounce like a ball when thrown. However, it is also alive, able to move on its own and consume anything it can envelop, including people and animals, to add to its mass. In addition, any living thing that consumes Monster Blood will grow several times their original size.


Goosebumps (original series)

Monster Blood

Monster Blood (Cover)

Monster Blood makes its debut in this book, where it is found in an old toy store in a dusty metal can opened by Evan Ross and Andy. It's innocuous at first, cool to the touch, glowing, stretchy, and bouncy. It evolves and becomes warm, sticky, and bubbling. Soon after Evan and Andy open the Monster Blood, Evan's dog Trigger eats some and grows very large. The Monster Blood itself grows larger and larger as the story progresses, eating several objects and even a couple people. It's later revealed that the Monster Blood's abilities were caused by a spell cast by a witch named Sarabeth.

Monster Blood II

In this book, Evan initially has a dream involving his dog Trigger. In the dream, he notices Trigger has eaten Monster Blood. Soon after having this dream, only now in waking life, Cuddles the class hamster, eats some Monster Blood. Evan is then forced to eat some also in order to combat the gorilla-sized hamster. At the end, when the Monster Blood's expiration date kicks in, Andy gives Evan some more from Europe and Cuddles eats some more and the book ends.

Monster Blood III

In this book, Evan and Andy come up with a plan to get Kermit back with Monster Blood for getting on their nerves. Their plan goes wrong and Evan accidentally swallows some and grows at least two stories high. He then sticks Conan up a tree and plays a game of softball, though this doesn't last long, as he is a highly visible and unusual sight at his new height, attracting public attention. The police and fire department soon come, thinking he is an alien threat. Eventually, Kermit makes a formula at home which causes shrinking, allowing Evan to drink it. Evan wakes up the next day and is the size of a mouse.

Monster Blood IV

In the last book in the Goosebumps book series, Monster Blood comes in a can, but is blue, and multiplies when exposed to water. The blood is also carnivorous, evil, and has fangs. This blood is actually not a toy at all, but an aquatic military super weapon. The blue Monster Blood also makes a person multiply, when someone eats it.

Goosebumps HorrorLand

Monster Blood for Breakfast!

Gb hh03

In this book, Monster Blood is a "12 Hour Trial Strength" version, and it comes in a plastic egg. A character by the name Matt Daniels, grow about nine feet tall. The Monster Blood follows him to HorrorLand where it sucks up Sheena Deep and a Horror named Byron who saved Matt and Sheena's brother, Billy.

Goosebumps SlappyWorld

Monster Blood Is Back

In this upcoming book, Sascha Nelson and Nicole Miller use a can of "Monster Blood is Back" to help them win the Kids Big Chef Food Fight competition. However, the ooze begins to grow and cause mayhem once again.

Stage Adaptations

Goosebumps Live on Stage: Screams in the Night

Monster Blood was featured in the stage adaptation of Goosebumps. It is eventually used by Slappy the Dummy who grows into a giant.

Goosebumps (TV series)

Monster Blood appears in the Goosebumps TV series, in the episodes "Monster Blood" and "More Monster Blood", where airline food makes it shrink. It will only stop growing when it is put back in its jar. If a person eats it, they had better make sure some of it gets on their clothes; without doing so, their clothes will rip off if they continuing growing.

Video games

Goosebumps HorrorLand

Monster Blood is one of the Monster Cards that the player can collect throughout the course of the game.

Goosebumps: The Game

The player encounters the Monster Blood in the tunnels beneath Dead House, then a second time at the entrance to the attic.

Goosebumps Dead of Night

Monster Blood is seen on locked doors in Stine's house. It was stolen by Slappy the Dummy and used as a weapon as you chase him through the basement.

General information


Monster Blood has a very enormous appetite and would always swallow anyone or anything that gets in its way. However, the Monster Blood can never last forever as its magic would always wear out on an expiration date and if someone thought of a cure for its effects. But every time one opens the Monster Blood, they are doomed and are in even more trouble if they swallow it.

Physical appearance

Monster Blood is a slimy green substance that is usually either cold or hot. On the cover of Monster Blood for Breakfast! and the Classic Re-Print of the first Monster Blood, it has a sentient form and face.

Variations and similar substances

Asides from the ordinary green variant, there actually are also other variations of slime that are used in a similar fashion:

  • Purple Peanut Butter: this is a jelly-like substance that — when consumed — has the opposite effect of Monster Blood (i.e. the consumer shrinks).
  • Blue Monster Blood: this substance starts as an ooze, but it becomes a creature that can multiply whenever it contacts water. Every time it multiplies, it becomes meaner. While this substance is originally presented as a new form of Monster Blood, it is entirely seperate.
  • "Twelve-hour version": this is a variant of Monster Blood that is only effective for twelve hours. It appears in the book Monster Blood for Breakfast!.
  • "Vampirism Goo": (also known as "Vampire in a Can"): this Monster Blood-like goo can turn whoever consumes it into a vampire. It actually has no legitimate relation to Monster Blood, but it works in a fashion much similar to it.

List of appearances


Title Role Release date Series
Monster Blood Main antagonist July 1992 Goosebumps
Monster Blood II Main antagonist April 1994 Goosebumps
Monster Blood III Main antagonist March 1995 Goosebumps
Escape from the Carnival of Horrors Cameo July 1995 Give Yourself Goosebumps
Beware of the Purple Peanut Butter Obstacle June 1996 Give Yourself Goosebumps
Monster Blood IV Mentioned December 1997 Goosebumps
Goosebumps Live on Stage: Screams in the Night Antagonist August 1998 Standalone
One Night in Payne House Mentioned October 1998 Give Yourself Goosebumps
Return to HorrorLand Mentioned January 1999 Goosebumps Series 2000
Monster Blood for Breakfast! Main antagonist May 2008 Goosebumps HorrorLand
Monster Blood Is Back Main antagonist March 2021 Goosebumps SlappyWorld

TV series

Episode Air date Season
"Monster Blood" November 16, 1996 Season 2
"More Monster Blood" November 16, 1996 Season 2

Live Events

Title Role Year of Production
Goosebumps Live On Stage Enemy 1998

Video games

Title Role Release date Platform
Goosebumps: The Game Enemy October 13, 2015 Nintendo 3DS, Xbox 360, PlayStation 3, Xbox One, PlayStation 4, PC
Goosebumps Dead of Night Enemy/Weapon June 19, 2020 Xbox One, PlayStation 4, PC, Nintendo Switch


  • In Monster Blood II, it is revealed that Monster Blood has an expiration date, causing the magic to wear off. This is the only known way to defeat the Monster Blood (in the books).
  • In Monster Blood II, it is revealed that Monster Blood is sold in Europe (Germany).
  • In the television episode, the Monster Blood seems more bouncy and sensitive to the touch.
  • In the television episode, the Monster Blood was a substance created by Sarabeth, while in the book it was a normal toy that had a spell put on it.
  • Monster Blood also appears in the Give Yourself Goosebumps books, Escape from the Carnival of Horrors and Beware of the Purple Peanut Butter. It is also mentioned as a puzzle in One Night in Payne House (the reader needs to know the color of Monster Blood, in order to solve something.)
  • The blood in Monster Blood IV is not the regular Monster Blood, but actually an aquatic military super weapon. This blood multiplies when it is exposed to water and more resembles slugs or snails than slime. The blood has eye stalks, and mouths with razor sharp teeth. However, like the original Monster Blood, if you eat it, you will change, as you become mean, can't stop drinking water, and multiply when you eat the blood in Monster Blood IV.
  • In Monster Blood for Breakfast!, the Monster Blood comes in a plastic egg like Silly Putty and is sold on a shady website that can damage the computer of whoever orders it.
  • The green Monster Blood shares many similar qualities with the alien from The Blob and the 1988 remake of the same name.
  • Monster Blood did not appear in the 2015 film Goosebumps as one of the monsters unleashed by Slappy. However, Monster Blood was only mentioned in the film.
  • A green substance resembling Monster Blood appears on the front cover illustration of the Goosebumps SlappyWorld book Diary of a Dummy.
  • Monster Blood appears as a weapon used by Slappy in Goosebumps Dead of Night.
  • The Monster Blood shouldn't be able to grow after the first book since Sarabeth, the witch who cursed the Monster Blood, dies at the end of the end of the book. This causes the Monster Blood to shrink. This means that the books Monster Blood II, Monster Blood III, and Monster Blood for Breakfast! shouldn't grow or be able to make things giant. Even if Sarabeth curses all the Monster Blood in the world, all the Monster Blood would shrink away.
    • However, it is possible that with Monster Blood for Breakfast! focusing on a brand new protagonist with no connection to Evan Ross or the others, the canon for this version of Monster Blood is completely different.



Regional depictions

TV series

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