Action Frank was born Akshunt Frank Franklyn to wealthy a Dutch-American family, heirs to a vst cookie importer fortune. Born with an asymmetry of the skull, doctors advised he wear a helmet from birth to help re-shape the bone. Much like a shark though, Frank's physiognomy actually contains no bone and his skeletal structure is made up entirely of cartilage, so his head never did come together.
In embarrassment, the family left young Akshunt to the care of "DWEeB" (Doctors With Expertise en Bupkus), a secret underground society to raise and experiment on at their will, and officially disowned him and destroyed all documentation linking them to him. The Doctors at DWEeB performed physical and phsycological tests on the boy, the horrors of which would drive any normal man insane. They convinced him he could speak with animals. They convinced him he had been born with a prehensile tail, then told him it had been mangled in a horrible thresher accident, just so they could monitor the phantom pain conjured in his addled brain.
There were many more, but I understand some of you are eating while reading this.
Young Akshunt eventually escaped the mad doctors, made his way to a grand jury and testified against their nefarious schemes. He then became a ward of the state, until he was assigned under the guardianship of the handsome, wealthy, benevolent Geoffrey Von Oberdorfer IV.
He would along the way trade in the football helmet he wore to protect his undeveloped skull for a more sporty pith helmet. He explains the practicality of this by saying, "No matter where you go, if you have to take a pith, it's right there!"
Then he found that "Husband"ry wasn't as erotic or romantic as it sounded, and gave up.