- The series is pretty much void of disturbing things, but "The Opera" is an exception. "Crazy" Joe Davola, who was already creepy/threatening in his behavior towards Jerry and Kramer, was stalking Elaine, as revealed when she comes to his apartment and finds tons of covertly-taken pictures of herself on his wall, including one when she was in the shower. As if that wasn't bad enough, when she tries to leave, Joe shuts the door and blocks her path. It's only after she pepper sprays him that she can escape. It's very possible she could've been raped and/or held captive had she not gotten out of there.
- In the same episode, the whole creepy clown motif can make the episode unnerving for those who suffer from coulrophobia.
- The Lopper in "The Frogger" is a pretty grisly unseen character, a serial killer who went around decapitating people. And he was still on the loose during the events of that episode.
- The imagery of George sitting all alone at Reggie's, with no laugh track and the camera ominously zooming out, is fairly unsettling.
Nightmare Fuel / Seinfeld