|Date of Birth||1991|
|Powers and Abilities|
Gwendolyn "Gwen" Tennyson is the cousin of Ben Tennyson and the girlfriend of Kevin Levin. She is also the granddaughter of Max and Verdona Tennyson, sister of Kenneth Tennyson and daughter of Lili and Frank Tennyson. She is also the good friend of Victor Cromwell and his wife Karen Walker.
Before the Omnitrix
Before her last day of school for the summer, Victor Cromwell and her had plans for the summer to hang out, however her plans changed when her cousin Ben and her grandfather Max took her on a summer long camping trip. Victor understood what was up, so he was on the road for a while until he met Karen Walker.
5 years later, Gwen, Ben and Kevin were investigating recent Highbreed activity in Bellwood. Victor and his wife were on vacation so they decided to visit the alien trio. Once there, they decided to help Gwen find and stop the plans of the Highbreed before things really got out of hand, but Gwen promised that they would catch up on old times afterwards. They eventually discovered that the Highbreed were within the shipping yards of Bellwood, but since Kevin's car was busted, they took Anodite 1 to the shipping yard. They managed to sneak in the yard, but Gwen got herself caught and detained, so Victor, Karen, Ben and Kevin engaged the Highbreed. Once they stopped them from sending for their troops, Victor and Karen released Gwen and stopped the portal that was going to be used by the troops before they even came. Afterwards, they all went out for a couple of smoothies and then Victor and Karen left, saying their goodbyes for now.