With his brown, wrinkly skin and glowing index finger, we all thought E.T. had an aesthetic that was all his own.

Turns out he was actually a little bit Albert Einstein, a little bit Ernest Hemingway and a little bit Carl Sandburg.

When it came to creating the iconic extra-terrestrial, director Steven Spielberg advised special effects artist Carlo Rambaldi to look to the theoretical physicist, the esteemed novelist and the Pulitzer prize-winning poet.

“I remember saying to Carlo, ‘Here’s some pictures of Albert Einstein, Ernest Hemingway and Carl Sandburg. I love their eyes. Can we make E.T.’s eyes as frivolous and also wizened and as sad as those three icons?’ ” Spielberg says in the featurette, “The Making of ‘E.T. The Extra-Terrestrial.’ “

The unexpected inspirations proved effective. Rambaldi, who had previously worked with Spielberg on the aliens in “Close Encounters of the Third Kind,” won an Academy Award for his work on “E.T.” It was his third Oscar, following wins for his work on Ridley Scott’s “Alien” and John Guillermin’s 1976 remake of “King Kong.”

But “E.T.” was the Italy native’s crowning creation. Upon Rambaldi’s death in 2012 at age 86, Spielberg called him “E.T.’s Geppetto.”

This month marks the 40th anniversary of Spielberg’s childhood classic. The film ran in theaters for an unprecedented full year, until June 1983.