To celebrate the spooky shenanigans, Yahoo Entertainment talked to one of the film's leads, Dee Wallace, who memorably portrayed Mary, the divorced single mom of alien-harborers Elliott (Henry Thomas), Michael (Robert MacNaughton) and Gertie (Drew Barrymore).
"I had to go over to the studio, behind closed doors, and read the script," Wallace, 70, recalled about her entry in the E.T. universe (watch above). "I called my agent and said, 'Look, I don't think it's going to do a lot for me, but I think it's going to do a lot of the world, and I want to be a part of it.'"
The beloved fantasy became the highest grossing film of all time when it passed 1977's Star Wars, ultimately racked up more than $359 million in the U.S. alone (or 1.4 billion packets or Reese's Pieces), plus an additional $75 million from international releases, good for worldwide haul of $663 million.
Wallace revealed that the trick-or-treating scene was actually filmed on Halloween, and Spielberg came to set on wearing the same outfit Gertie put on E.T. while playing dress-up, much to the dismay of Elliott. "Steven came in dressed exactly like E.T. was dressed," she said. "With the hat and the pearls and the dress. The kids just freaked out."
The actress also explained how two unscripted, off-the-cuff moments made it into the film: walking away from the kids in tears after Elliott laments that he can't call his father because "he's in Mexico with Sally," a new girlfriend, and the laughter she couldn't contain while attempting to scold Elliott for his famous "penis breath" outburst.
But Wallace's most profound memory came from among the countless fan reactions she has heard over the years.
"For sure the most touching one was a mother that came up and said, 'Miss Wallace, I just want you to know, you're part of a miracle in my life. My son's autistic, I had never heard him speak for 10 years. And I took him to see the re-release of E.T. and on the way home he started saying every line that E.T. said.'
"I mean, can you imagine not hearing anything come out of your child for 10 years and then [that]."
It's a story that captures the universal magic of E.T.
Or as Wallace put it, "There's something about that movie that reminds our hearts of what's true. It goes inside you and it opens up places. It's a magical film. It's our Wizard of Oz. It's going to live forever."
Watch the "scream queen" Wallace talk about her most famous horror roles:
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