Line a baking sheet with parchment and set aside.
With an electric mixer, mix peanut butter, butter and vanilla extract until light and smooth.
Add powdered sugar one cup at a time mixing thoroughly after each addition.
Take about a tablespoon and a half of dough and make it into a round ball. Place on prepared baking sheet.
Repeat with the remaining dough.
Once all balls are formed, place them in the fridge for at least one hour.
Melt melting chocolate and divide into three separate bowls.
Color each portion desired color.
Prepare a separate baking sheet or plate with parchment. This will be where you decorate your monsters.
Take balls out of the fridge. Place a ball on a fork and use a spoon to cover the ball with melted chocolate.
Once the ball is coated, tap the fork on the edge of the bowl to remove excess chocolate.
Place coated ball new parchment sheet and use sprinkles to decorate as desired.
Set aside until chocolate is dry.