“SNL50” delivered another Kate McKinnon-led alien abduction sketch, with some especially big names making a surprise appearance, including Meryl Streep, who showed up as McKinnon’s similarly filthy-mouthed mother.

“We are eager to talk to you as you have all experienced a verified alien abduction,” a government official played by Aidy Bryant asked a disheveled McKinnon, Pedro Pascal and Woody Harrelson as they were joined by a fellow Pentagon employee, played by Jon Hamm. “Let’s start with how you were all brought aboard the spacecraft,” Hamm said.

“This beam of light appeared from the bottom of the ship, lifting me up like a soft hand,” Pascal said, with Harrelson adding, “we met these two beautiful, glowing aliens who took our hands and said, ‘welcome’ — I’ve never felt so safe.”

McKinnon, who reprised her role as Ms. Rafferty, had a bit of a different experience, recalling “I was...