Mighty Mom and Dyno Dad are Timmy's parents' alter-egos created by one of Timmy's wishes. Mrs. Turner turns into Mighty Mom and Mr. Turner turns into Dyno Dad.
Mighty Mom and Dyno Dad are actually Mr. and Mrs. Turner's superhero forms, when Timmy feels the need for them. They first appeared in the episode, "Mighty Mom and Dyno Dad", when Timmy was sick of his parents not having the energy to do anything after their work. However, with their superpowers, they become busier than ever, "making the city safe for Timmy," that Vicky had to babysit all night. So Timmy decided to become the world's most powerful supervillain, Galactimus, Eater of Planets, in order to get them to give up their powers willingly. However in "The Crimson Chin meets Mighty Puff and Dyno Dad", Timmy wished that his parents were superheroes again to combat the Nega-Chin and his supervillain pals. However, they were defeated once again, by Nega-Chin's Negavision.
It's suspected that they were Mighty Mom and Dyno Dad in "The Big Superhero Wish", since everyone was either a superhero or villain.
Both wear blue spandex suits with yellow capes, white belts, white boots, and Eye masks. Mighty Mom has an MM on her chest, showing her neck and torso, much like Wonder Woman, and golden bracers on her arms. Dyno Dad has a DD on his chest. In their "secret identity forms", they wear mild-mannered suits and horn-rimmed glasses, like Clark Kent.