|The characters and/or events depicted in this article belong to an alternate timeline or dimension.|
|Home World||Earth (RAT Timeline)|
|Relatives|| Ben Tennyson (son)|
Gwen Tennyson (niece)
Max Tennyson (father)
Sandra Tennyson (wife)
|First Appearance||Ben 10: Race Against Time|
Carl is depicted as a new-age style parent who wants Ben to have his "freedom," insisting on being called "Carl," not "daddy," "dad," or "father," and letting Ben run off on mysterious adventures without asking questions. Carl wants Sandra to give Ben some freedom.
He seems more laid back than Sandra, and is seen at least twice telling her to let Ben have his fun. For instance, near the end when Sandra tells him to not eat too much cheese, Carl says to "Let the kid live a little. Eat all the cheese you want, Ben!"
- Carl seems to contradict Sandra when it comes to disciplining Ben, being more loose than stern, though like Sandra, he insisted to be called by his name.
- Like Sandra, his look in the movie would eventually be used for his main timeline counterpart.