Claim: Frank Lentini (1881-1966) had three legs, four feet, sixteen toes, and two sets of functioning male genitals.
It’s true.
His “extra” body parts were part of an undeveloped conjoined twin that could not be removed. He was able to fully control his third leg, and learned to kick a ball with it, which he did as a circus performer for nearly 20 years. He was married, had four children, and lived to the age of 77.
A photo of Lentini was used on the back of the 1995 Alice in Chains self-titled album which featured a three-legged dog on the front cover.
Source
Biography of Three-Legged Wonder Franceso A. Lentini Part 1 (Trivia Library)