Also known as "The Green Warrior", Emerald discovered Earth when she escaped from Homeworld's rule about 200 years ago. She got the idea to become "The Green Warrior" about the mid-1940s when superhero comics were just starting to get popular, and now fights crime during the night, and corrupted gem monsters during the day.

As a gem, her body does not need food, drink or sleep. In fact, she only sleeps very occasionally, and she refuses to swallow anything. But that doesn't mean she can't enjoy flavors and scents. She actually likes chewing gum and bubble gum.

Her weapon is a mallet of changeable size, she possesses all the standard gem abilities, and she can also exert some control over plant life, such as wrapping up bad guys with vines after knocking them out. She's about the height of a 13 year old girl, her weight doesn't matter, and she's existed for about 1000 years., fairly young by gem standards.