A creature that stalks you in the night waiting for when ur not looking and snatches your grundle. This creature is 3 ft tall, purple, hairy, makes a sound similar to "GIHEE", and can reach the speed of 47 miles per hour.
*note* a grundle monster is the exact same thing as grundle troll
God Damnit, that grundle monster stole my grundle. Now i have to shit on my balls because my grundle has been stolen.
Grundle - The area between your asshole and your balls.