|This article belongs to the Classic Timeline|
Frank wears glasses and has thin brown hair. He wears a smart polo shirt with a burgundy sweatshirt covering it. He also wears tan trousers.
Frank is a considerate father who'll let his daughter, Gwen, make her own decisions. He is understanding and can stay calm, even in unexpected situations.
He was introduced in What Are Little Girls Made Of?. When Gwen told him about her powers, he said he hoped that the day she met her grandmother would never come. He does not have "the spark" that his daughter has and that gives her her powers. However, Verdona states that he always knew when she was eavesdropping on him while being invisible to the human eye. He initially assumed that Gwen was going out with Kevin without telling him or her mother, much to their embarrassment.
In Grounded, it was revealed that Frank apparently already knew about his father's life in the Plumbers, but unlike his brother, he accepted this fact but tries hard to avoid getting off on the wrong foot of Carl. When Ben's possession of the Omnitrix over the past five years comes to light in front of Carl and Sandra, Frank is informed of Gwen's involvement by his brother, prompting him and Natalie to lecture their daughter about ‘deceiving‘ the family for her cousin before grounding her.
- What Are Little Girls Made Of? (first appearance)
- Frank and his brother, Carl, were both born human, as neither of them have "the spark". However, they are able to detect mana-based activity to a limited extent, thereby can sense whenever their mother is nearby.
- Frank and Carl only found out about their mother being an alien when they were adults.[DM 1]
- Frank and Natalie are more conservative than Carl and Sandra.[DM 2]
- Frank and Natalie don't like Kevin but are too smart to forbid Gwen from going out with him.[DM 2][DM 3]
- Manny Tennyson was mentioned in Gwen 10, a non-canon episode. It is unknown if he exists in the canon timeline.