The Blue Beast is a minor villain from the adventure videogame King's Quest V: Absence Makes the Heart Go Yonder. It is a blue creature that is the only henchman of Mordack.
Nothing is known of the Blue Beast's past but on some point it became a henchman of the evil wizard Mordack.
The Blue Beast roams the halls of Mordack's castle and does not eat or sleep at all. Instead it just wanders the halls to pursue and catch intruders to take them to the castle cell.
The player must be caught by the Blue Beast only once to complete the game. If Graham is caught a second time, the game is over. Graham defeats the Blue Beast by dropping dried peas on the floor and the Blue Beast trips on them and is stunned when it lands on the floor. It does recover, however, and must be avoided if the player sees it.
The Blue Beast is shown to be part ram and part praying mantis. It is very strong and very fast. Many players can have difficulty avoiding the Blue Beast but it is important that they be prepared for it when it comes.