After Tarzan made his first appearance in the early years of the twentieth century, the popularity of the character took off like a sky-rocket. So it should be no surprise that the world of pulps and comic books wasted little time in converting that success to other forms with other, quite similar characters.
But comics... comics were filled with Tarzan clones left and right. I am sure if you checked out a comics rack in the first half of the forties you could find half a dozen titles with jungle themes. Characters with names like Ka'anga and Wambi appeared, while early female star Fantomah was an insanely over-powered (and sometimes skull-faced) protector of the jungle.
Things really went up a notch following the debut of Sheena, Queen of the Jungle. The Eisner-Iger creation was one of the most popular characters of the thirties and forties, surviving until 1953. She spawned a pulp during that time (a feat rare among comic books). She returned in a short-lived TV series, a movie in the mid-eighties, and a very entertaining comic from Devil’s Due just a couple years ago.
After the forties, the Tarzan clones became more sporadic. In France rival comic publishers created Akim and Zembla, both long lasting jungle lords. Marvel debuted a new Ka-Zar while DC dug back in to public domain Victorian fiction for the character of Rima. Parodies like George of the Jungle would also soon crop up. Wherever he appeared, the character of Tarzan seemed ready to appear in any number of variations in any place or time.
I suppose it is the mark of a truly defining character. Whatever the case, it seems Tarzan will live on, in one form or another, for a very long time to come.