The first time the character appeared in live-action was in the prospective television pilot for a "Wonder Woman" TV series entitled "Who's Afraid of Diana Prince?" in 1967. Clearly inspired by the successful "Batman" series of the time, Elle Walker plays Diana, who lives with her nagging mother who demands she not go save the world on an empty stomach. She does, briefly, become Wonder Woman (and is then played by Linda Harrison), but mostly it looks like a zany comedy about a man-crazy single woman who sometimes saves the world. It's... not good.
Wonder Woman's animated debut came along a few years later, and may be even less noteworthy, as she's not even the star. In the 1972 episode of "The Brady Kids" animated series, itself a spin-off of "The Brady Bunch" but with fewer parents and more magical talking birds with the voice of Larry Storch (as was the style at the time), Jan Brady visits the university library in order to research Euclid and meets librarian Diana Prince. When the aforementioned magical talking bird zaps them back to ancient Greece, zaniness ensues.
As with much '70s kids animation, it's pretty awful, and the randomly-appearing laugh track (which even goes off when Wonder Woman makes her first appearance!) doesn't help matters any. At least Wonder Woman gets to do something and the Grecian setting pays some reference to her origins, so it's mildly better than the 1967 pilot -- or it would be, if it wasn't over four times as long.
