Horror clown masks are part of Gary Marshall's collection of over 280 masks and figures on display in his home, Thursday, Oct. 24, 2019, in Pilot Mountain, N.C.

“Treehouse of Horror XXXI,” which airs on Oct. 18 at 8 p.m. on Fox, opens with an election parody that’s not for the faint of heart.

The grotesque mask from the 2012 horror movie “Smiley” (left) recalls the smiley emoticon. It’s well-matched to the movie’s theme, about a killer who can be summoned via the internet to ...