Biggest pro football accomplishments: Made four Pro Bowls while playing defensive tackle for the Lions
Biggest pro wrestling accomplishments: Took part in matches against fellow NFL player William "Dick the Bruiser" Afflis that drew a lot of attention in Detroit
The key to his career change: He was forced to wrestle professionally in the middle of his NFL career after he admitted to gambling and was suspended from the league from 1962 through 1964.

There's not a whole lot of information out there about Karras' wrestling career. But what is known is that he agreed to wrestle during his suspension from the NFL because he needed a source of income. So he spent about a year and a half squaring off against guys like Dick the Bruiser before resuming his NFL career.