Gwendolyn Tennyson is the future version of Gwen Tennyson.
Gwendolyn has short orange hair that has bangs in the front. She wears a blue and black spandex suit and the Charms of Bezel on her right arm. She has a hood and only sometimes wears it. She has a belt with a cat on it, the same cat Gwen wore on her shirt when she was ten.
In Ken 10, Gwendolyn has much longer hair, tied back in a ponytail.
In The End of an Era, she looks more like she did in Ben 10,000. However, the lines on the Charms of Bezel are thicker, and colored pink. The cat symbol on her belt is a different shape, with pointier ears and pink eyes. Her shoes now have white toes and outsoles. She also has freckles and blue earrings.
In Ben 10,000, 30 year old Gwendolyn came through a portal to the Main Timeline and grabbed Gwen to lead XLR8 into her timeline. When Ben and Gwen were there they believed the "crisis" Gwendolyn was talking about was Vilgax and Dr. Animo. At the end of the episode Gwen realized that Dr. Animo was never the crisis, Ben 10,000 just needed a major attitude adjustment.
In Ken 10, 42 year old Gwendolyn appeared as a hologram and gave Ken a Stone Creature as a birthday present. Later in the episode, she and Ben 10,000 were discussing whether or not Ben 10,000 should let Ken fight.
In The End of an Era, she attends Max's retirement party alongside Kevin. When the power goes out, she helps the other guests evacuate. She helps Ben and Kai battle Maltruant, but ends up being temporarily frozen in time.
Ben 10: Omniverse
- The End of an Era (first re-appearance)
- According to herself, Gwendolyn started going by Gwendolyn instead of Gwen since college.