Gwendolyn Catherine Tennyson is an Anodite and Ben Tennyson's cousin. She is currently in a relationship with Kevin Levin.
Gwen is kind-hearted and loyal to Ben. She loves Kevin Levin deeply.
Gwen can control magic, mana and other energy substances.
Ben 10: Omniverse Good VS Evil
Ben 10 Omniverse: Good VS Evil
- New Beginnings: She appears through the episode arguing at Ben because he thinks he is a solo hero. She later fights Khyber and wins.
- A Plumber's Betrayal: Gwen encourages Rook to be confident when meeting Nova. She later fights Kalibur and succeeds when Magister Laxine helps.
- Piscciss Under Attack: Gwen fights the cyborgs and is later injured. She is later healed and leaves.
- Dr Animos Mutation:: Gwen fights Dr Animo.
- New Beginnings
- A Plumber's Betrayal
- Piscciss Under Attack
- Dr Animo's Mutation
- Her powers have grown in the new series.
- She always misses Kevin whilst he is on Osmos V.
- Gwen appears to have mentioned that she wants Kevin to propose to her.
- Gwen will play a big part in the Ben 10: Omniverse Good VS Evil Movie.