The Blue Alien is one of the characters in Putt-Putt Goes to the Moon.
The Blue Alien will act as the referee of the Alien Tag mini-game. He appears when Putt-Putt clicks on the crater to his right. After Putt-Putt accepts to play the mini-game, he will go back into his crater to start the game. When the game is over, the Blue Alien will give Putt-Putt Glowing Moon Crystals equal to the number on the large rock behind Putt-Putt.