*In her human form, Crystal is a slender, tall, tanned woman, almost matching Shaggy's height, with long, ravenous black hair with a navy-blue shine and honey-brown eyes. As Crystal is not a native from Earth, she sets her human disguise based on the television signals from the 1960's she picked up from her planet. Thus, her outfit is reminiscent of a stereotypical hippie girl from the 1960's. She wears an orange T-shirt with a brown studded belt, a matching orange headband, light blue bell bottom jeans, brown moccasins, light brown lipstick and a peace sign necklace.

As an alien, Crystal towers over Shaggy in height, but she still maintains a distinguishable feminine hourglass shape. Her head is large and bulbous, common to the stereotypical appearance of a Grey alien, and she has large eyes. Her light blue body is translucent and composed mostly of fluid, with several bubbles moving around beneath her skin. The strange blue coloring also gives the resemblance of glass, making her name literal in a sense. She also appears to have three fingers on each hand.

Crystal is kind, feisty, gentle, jolly, sweet, charismatic, curious, stubborn, laid back and charismatic. She understands Shaggy's sense of humor and even speaks similarly to the way he does by starting sentences with the word "like" and using "groovy." Crystal is brave, unlike Shaggy and Scooby, as showned when the imposter MP's forced them to leave the cave area where they saw the jackalope and ultimately: the aliens. After walking a distance away from the cave, she immediately wanted to go back.

Being a government agent from another planet, Crystal is very dedicated to her task. She relies on her knowledge of the human culture she had learned and applies her style of speech and fashion to blend in with Earthlings. This trait makes Shaggy develop a romantic interest in her, who shares the similar 1960s hippie subculture synonymous with her guise. Despite their romantic feelings for Shaggy, Crystal wants to keep her true identity a secret from Shaggy. Crystal admits her flaws of deceit to him, showing she did care and valued his friendship to be as honest as she could about her occupation and actual alien form when they were in danger.

In the end, Crystal really did have feelings for Shaggy but seemed to try to keep anything romantic from happening between them, knowing that, in the end, "long-distance relationships never work out."

Crystal has the ability to change her appearance using an image-changing device that symbolizes a peace symbol pendant hanging on her neck. Being an alien from another planet, Crystal possesses a high level of intelligence. She can speak English very fluently and has obtained a vast knowledge of human culture from one of Earth's broadcasts she picked up back on her home planet in order to fulfill her human disguise.*