|Species|| 3/4 Human
|Powers|| Mana Control|
|Voice|| Megan Smith (OS)
Ashley Johnson (AF,UA,OV)
|First Appearance||And Then There Were 10|
Gwen Tennyson is a fat nerd
Gwen is 10 years old in the original series. She had short orange hair. She wears a blue shirt with a cat on it and white pants. Her hair is held by a clip. She has green eyes, like Ben. As Lucky Girl, she wears a black suit with a mask.
Ben 10: Alien Force/ Ben 10: Ultimate Alien
Gwen is 15 in Alien Force. In seasons 1 and 2, she wore a blue shirt and a skirt. In season 3, she wore a different outfit. In Ultimate Alien, she wore another outfit.
Ben 10: OmniverseIn The More Things Change: Part 1, Gwen's outfit was similar to her outfit in season 1-2 of Alien Force. In the new episodes she appeared in, she has shorther hair and wears glasses. She wears an outfit similar to her Original Series outfit.
Gwen Tennyson can be a very gentle girl, however since she is stuck traveling the world with her cousin Ben she is often very aggressive as they are always fighting. She loves her family and enjoys spending time with them except when they don't act to her expectations. Gwen seems very smart especially with technology because she can look up anything very fast on her laptop. Although Ben constantly annoys her, she seems to care about him. An example can be in Back With A Vengence, when she went in the Null Void to save Ben.
Early in the series, Gwen has no powers and must rely on her fighting skills. She is a very skilled fighter as she has been studying karate. She also knows how to use a fire extinguisher. After switching bodies with Charmcaster, she begins to study magic, and becomes proficient in it, using it to aid Ben in his fights.
By Alien Force, she learned to use mana. She started this in Destroy All Aliens.
Gwen Tennyson lately joined Team Tamtaro and helps Tammar fight against the great gods of Team Oprah.
In And Then There Were 10, Gwen was introduced when Ben discovered, to his dismay, that she was joining him and Max on a road trip. She was not happy to be there, either. At the campsite, she fought with Ben, causing him to walk into the woods. When she and Max noticed a forest fire, they ran to put it out. Gwen found Heatblast and quickly realized who he was. Later, when Ben turned into Wildmutt. she tried to take advantage of his having no eyes to hit him, but she failed. After Wildmutt turned back into Ben, Gwen saved him by destroying one of Vilgax's Drones with a shovel. Ben later repayed her by saving her from a tree that was about to collapse on her.
In Washington B.C., she helped Ben and Max catch some thieves. Later, she caught Ben going through cereal boxes in a store to look for a Sumo Slammer card, and ended up taking the blame, which greatly annoyed her. After Dr. Animo attacked, she researched him and figured out his plan. However, she was then kidnapped by Animo's Bird. Stinkfly rescued her, returning her to Max.
In The Krakken, Gwen didn't believe Ben when he said he'd seen a sea monster. When Ben and Max went fishing with Captain Shaw, she stayed behind and relaxed on the docks. Later, she researches Jonah Melville and discovers that he is actually a poacher.
In Tourist Trap, Gwen accidentally helps to free the Megawhatts from "It" making her afraid that she will get in trouble. It shows how much of a goody goody she can be and how different she is from Ben. She ends up not getting in trouble and learns a thing or two from Ben about lying.
In Kevin 11, Gwen goes with Max and Ben in a hotel. After they were kicked out, Max left to do somthing. Ben wants to leave but she warns him not to. Throughout the episode, she helps Max find Ben.
In The Alliance, Gwen helped Max when he was in the hospital. She didn't really make an impact because the episode focused on Ben more.
In Last Laugh, after the trio head to the circus, Zombozo tricks the audience and captures them, and Gwen was one of them. He wanted to feed on their happiness. Ben attempts a rescue as Ghostfreak but Gwen was zombified. However, Ben defeated Zombozo and rescued everyone.
In Lucky Girl, the episode focuses alot on Gwen. After Ben gives her a luck charm, she decides to be a hero called "Lucky Girl". Then Hex appears and wants her charm so he can collect all the charms and take over Earth. Then, Gwen (Lucky Girl) and Four Arms defeat him. They chased him throughout the museam. After the defeated him in a cemetery, Gwen destroyed the charms of bezel.
In A Small Problem, Gwen was playing with Ben in a water park. After Ben (As Grey Matter) was kidnapped by a human who wanted to sell Grey Matter to the Forever Knights, Gwen helps Max find Ben. She searched many houses and found Ben because they found Larry's phone. She then rescues him from the castle and at the end, her picture is shown in Enoch's computer because he wants to find them.
In Truth, Gwen stayed with Ben in the hotel but he took her as XLR8. Later, she hid in Phil's car and wanted to destroy the Null Void gun but he grabbed it, however, Ben (As Grey Matter ) and Gwen defeated him.
In Gwen 10, she is highly focused on. Note that this episode is uncannon. It is also similar to And Then There Were 10. In this episode, the setting is rebooted to an alternate universe and it is the start of summer and when the trio go to the camp site, Gwen gets the omnitrix. Gwen used Heatblast, Grey Matter, Diamondhead, Upgrade, Ripjaws, XLR8, and Four Arms. At the end of the episode, the Omnitrix goes to Max. For more information, see the episode page, all you have to do is click here.
In Camp Fear, Ben and Gwen argue about their 11th birthday. Gwen is later trapped in the camp because of the mushroom monsters. She then leads the campers to fight and to glory. In the end, Ben and Gwen learn a valuable lesson about sharing.
In Tough Luck, the episode focuses on her. Charmcaster breaks Hex out of jail. They seek the charms of bezel. The trio try to defeat them. At the end, Gwen loses her powers but she tricks them by going up a window cleaner. For more details, see the episode page by clicking here.
In Back With A Vengeance, Gwen goes in the Null Void to save Ben from Vilgax and Kevin and she took the Omnitrix and replaced it with a bomb which exploded on Vilgax.
In Ben 10,000, Gwen goes to the future with Ben and unites with her future self. She seems to be interested in knowing about her future and she helps her future self and future Max defeat Dr. Animo.
In Game Over, Gwen is stuck in the video game alongside Ben and the fat sumo slammer thinks that Gwen is a better warrior than Ben.
In Super Alien Hero Buddy Adventures, Gwen and Ben are trying to figure out who kidnapped Kangaroo Comando. In Under Wraps, Gwen is forced to work on a farm with Ben. She helps Ben find and defat the mummy (Or so they thought). By the end of the episode, Ben and Gwen left the farm.
In Don't Drink The Water, Gwen makes fun of Ben who is four years old. She helps him by mocking him, while he was Heatblast, to make an explosion.
In Ben 10 VS Negative 10, Gwen wants to take the tickets from Cooper, who really does not have them. She also uses magic to fight the Negative 10.
Ben 10: Alien ForceIn Ben Returns, it is discovered that Gwen joined a martial arts class. She is now 15. In this particular episode, she uses mana to fight. It is also her first love experience with Kevin.
In Kevins Big Score, Gwen helps Kevin get back to normal only to find another message from Max telling them to get as much help as they can.
In All That Glitters, Gwen wants Kevin to ask her on a date. She then scores a date with Michael Morningstar, who really just wanted to absorb her mana. He is later defeated. For more details, look at the episode page by clicking here.
In Max Out, Gwen wanted to find her brother, Ken. She convinces Kevin to drive them there. She later threatens a DNAlien to kill him if he doesn't inform her where Ken is. At the end, she rescues him.
In What Are Little Girls Made Of, Gwen and Ben's grandmother, Verdona visits. She tries to convine Gwen to become a full anodite. Gwen thinks about this, but when she refuses, a battle happens. By the end, Verdona is convinced that Gwen wants to stay a human. For more details, look at the episode page by clicking here.
In Unearthed, Gwen helps return the baby back to his parents.
In Vengeance Of Vilgax: Part 2, Gwen helps find the missiong aliens.
In Time Heals, Gwen goes back in time to cure Kevin. However, thsi turns out to be a disaster because Hex & Charmcaster take over the world leaving Ben as the only hope after Gwen dies. Gwen later goes back in time to stop her past self from telling her past past self to not hack the Omnitrix in the past.
Ben 10: Ultimate Alien
In Where The Magic Happens, Gwen helps Charmcaster fight her enemy. She also finds the third piece but Aggregor takes it again.
In Perplexhadron, Gwen goes into the box with Ben and Kevin. She gets frozen by Aggregor but Swampfire unfreezes her. She also helps find the final piece but Aggregor takes it once again.
In The Forge Of Creation, Gwen helps go to The Forge Of Creation. She is also annoyed by young Ben. At the end, she attempts to convince Kevin to be good, but she fails.
In the Kevin arc, Gwen tries to stop Ben from killing Kevin and she even fights him. By the end of the arc, he was saved.
In Girl Trouble, Gwen goes anodite and fights her cousin, Sunny.
In Creature From Beyond, Gwen is possesed by the Lucubra but she is soon saved.
In Basic Training, Gwen must be trained at the Plumber's Headquarters to earn her badge.
In Ultimate Sacrifice, Gwen goes anodite in an attempt to help Ben defeat the Ultimates but Ben soon stops her as he believes that the Ultimates have a life.
In Mother of all Vreedles, Gwen convinces the Vreedles to rejoin the Plumbers instead of helping their mom.
In The Enemy of my Frenemy, Gwen insists on helping Charmcaster. After Charmcaster finds out that Gwen dated Darkstar, she gets mad and they battle.
Ben 10: Omniverse
In The More Things Change: Part 1, Gwen helps fight Zombozo at the beggining. She then takes off to college with Kevin.
In Malefactor, 11 year old Gwen was with Ben and Max at the Plumber's Base to see Big Chill's predator.
In The Frogs of War: Part 2, Gwen, Kevin, and Argit come to Bellwood to fight the Incurseans after Ben is sent to space.
Ben 10: Alien Force
Gwen appeared in every episode and movie of the series.
Ben 10: Ultimate Alien
Gwen appeared in every episode of the series.
Ben 10: Omniverse
- The More Things Change: Part 1
- A Jolt From The Past (Flashback)
- Trouble Helix (Flashback)
- Of Predators And Prey: Part 1 (Flashback) (Mentioned)
- Many Happy Returns
- Malefactor (Flashback)
- Ben Again
- Showdown: Part 1 (Flashback)
- Showdown: Part 2
- The Frogs of War: Part 2
Ben 10: Protector of Earth
Gwen is a main character of the story, but she is not playable on consoles. On the DS, a cheat code unlocks a Gwen 10 skin, which changes Ben into Gwen and all of his aliens into Gwen variants.
Ben 10: Alien Force
Gwen is playable in two levels in this game.
- Gwen was meant to be Ben's classmate instead of cousin.
- Her favorite flowers are yellow roses.
- In the Original series, she owned a laptop that was seen quite often.
- In And Then There Were 10, it was stated that Gwen had a schedule to tell her what she was going to do everyday so she doesn't do the same thing twice.