Before making movies, good-looking Mike Henry played pro football for the Pittsburgh Steelers and later for the Los Angeles Rams, where his firm body was nicely showcased in those tight pants. It was while with the Rams that heterosexual Henry began acting. Sy Weintraub was a Rams fan and had seen a TV documentary about them called "Men from the Boys" produced-by and featuring none other than Mike Henry. In 1965 he was signed by Sy Weintraub to replace Jock Mahoney as Tarzan.
Born in 1936 in Los Angeles, Mike made 3 Tarzan films, all shot back-to-back between 1965 and 1966; Tarzan and the Valley of Gold (released 1966), Tarzan and the Great River (released 1967), and Tarzan and the Jungle Boy (released 1968).
The Tarzan franchise of that era attracted many of the same fans as the popular James Bond movies did, and it's reported that Weintraub wanted his next Tarzan to compete at the box office by being a sharp, sexy, and cool ape-man with lots of fast action to go along with the jungle adventure. The first movie's poster (below) with helicopters and modern weapons shows how far they moved in that direction. Hollywood folklore suggested that the reason Henry's Tarzan sported a hairy chest was to compete with Sean Connery's body carpet displayed in the Bond films. In terms of raw beefcake sex appeal, Bond's 007 couldn't match an almost-naked man wearing only a leather loincloth, and generated buzz (true or not) that the studio padded Mike's loincloth pouch to ensure a noticeable manly bulge. Then there are the ideas about that sheathed knife at his waist: To some, the knife's handle is similar in length, diameter and position to that of an erect upturned penis. After a little comparing of Tarzans, it does appear to me that this "big knife" was added to Mike's Tarzan and wasn't a prominent part of the standard loincloth for Jock Mahoney's costume. No doubt that sometimes "a knife is just a knife", and with that in mind, all I can say is that both the photos below and film trailer make it clear to me that this version of Tarzan was a heavily marketed product. Mike's character was packed with sex appeal. If I had to pick between only going to a Connery or Henry (Bond or Tarzan) movie back then, I think it would have been a tough choice to make!