Crystal is a female alien disguised as a human and owner of her dog disguised as Amber, and who is Shaggy's love interest from Scooby-Doo and the Alien Invaders.
About Crystal[]
Crystal and her golden retriever, Amber, found Shaggy Rogers and Scooby-Doo unconscious in the middle of the desert. Upon their awakening, she gave Shaggy some water and offered to give him and Scooby a ride back into town. Unbeknownst to both Crystal and Amber, the boys had fallen head over heels in love with them. After dropping off Shaggy and Scooby, Fred and the girls are bewildered when the boys are not hungry, shocking them all. During this ordeal, Shaggy daydreamed how his life would be like with Crystal in a song, "How Groovy".
Crystal, unfortunately, did not fulfill Shaggy's dream of being his when she later revealed herself to be a government agent from another planet. Crystal did end up having feelings for Shaggy but did not pursue them knowing she could never be with him. After the SALF employees were captured, Crystal and Amber's ship came to retrieve them from their mission. In a heartfelt goodbye, she kissed Shaggy on the lips hoping he would always remember her as a dear friend, leaving him heartbroken and devastated along with Scooby-Doo.