"Gwen" Tennyson, occasionally known as Lucky Girl, is a fictional character that appears in Cartoon Network's Ben 10 franchise, created by Man of Action. The paternal first cousin and best friend of title protagonist Ben Tennyson, Gwen is a core member of Ben's team who frequently aids him in his various adventures to defeat villains and criminals and protect and save earth and the universe. A highly intelligent and strong martial artist, Gwen later develops magic abilities.