Starla Gutsmandottir-Sorrenstein (also known as Muscle Woman) is a recurring character in Regular Show.
She is Muscle Man's girfriend (and later wife) and Mordecai's (former) girlfriend. In the end of "A Regular Epic Final Battle", Muscle Man and Starla finally have their first daughter. 25 years later, they have more than one child.
She makes her debut in "Muscle Woman" as the (former) main antagonist and became a protagonist later on.
Starla is a green humanoid with shoulder-length brown hair that is half down and half tied into two pigtail. She is about Muscle Man's build and is very similar in appearance. She typically wears a plain white long sleeved shirt in which her stomach hangs out of, a bluish-purple skirt, and a pair of black shoes. She has only dressed up differently on a few occasions, such as when her, Muscle Man, and her parents had dinner at Bistro en le Parc, and when she went rollerskating with Muscle Man in Bald Spot. As a teenager, she was shown to have been much skinnier and sported a different hairstyle. It is unknown how she acquired her green complexion. She is 4'9" although during the high school flashbacks she looks taller than she is now.
During the 25 year park reunion, she wears a purple dress, and her hair is still in two pigtails, only most of it is tied up instead of being half down and half up, and her bangs are styled different.
She was first introduced as Muscle Man's ex-girlfriend. When first meeting Mordecai, she began to develop a crush on him. As indicated by a tattoo on her lower back, she also dated two other boys (excluding Muscle Man). When Mordecai broke up with her (after briefly dating her), she became extremely angry and destroyed everything in her path, including the park. After being calmed down by Muscle Man, they rekindled their relationship.
Starla's personality can best be described as tough-as-nails. She will do almost anything to get revenge on someone who wrongs her and will gladly fight for her boyfriend, Muscle Man. Although she is often given more protagonistic appearances, she sometimes can be an antagonist as well. She practically destroyed the entire park in an attempt to get revenge on Mordecai for dumping her in "Muscle Woman", and she mercilessly broke Mordecai and Rigby's bones in a mud wrestling match in "Tent Trouble". Despite these two instances, however, she is often seen helping somebody out (Specifically Muscle Man). She willingly helps her boyfriend fight a bunch of evil waiters in "Fancy Restaurant", and she even encouraged him to win a hot dog eating contest against Death in "Last Meal". Also, despite being angry with him before, she now seems to be on good terms with Mordecai.