- Captain Obvious Reveal: Downplayed. Many viewers may be genuinely surprised to learn at the end that the gremlin was Real After All. Others might not realize they were ever supposed to think it was a hallucination in the first place, due to the facts that 1) it's shown to genuinely move out of view whenever Bob tries to show it to someone else, 2) weird abhuman monsters are par for the course in the Twilight Zone, and 3) mental breakdowns don't produce hallucinations.
- Nightmare Retardant: The gremlin is just a guy with comically oversized lips, wrapped in a not-that-scary costume that amounts to little more than a human-shaped shag carpet. The movie remake version was genuinely scarier-looking.
- Signature Scene: Bob looking right out the window to find the gremlin staring right at him.
- Values Resonance: Normally at the time, a character who'd recently been though something like a mental breakdown would've been female by default.
YMMV / The Twilight Zone S5 E123 "Nightmare at 20,000 Feet"