Before there was CG, there was Ray Harryhausen. He animated many "monster" or sci-fi creatures who populated the scary movies of my childhood, but the scene that stuck in my head the most over the years was the skeleton fight scene from Jason and the Argonauts.
A movie can mesmerize, but that scene TRIPLE mesmerized me (If there is such a term).
You can see a clip here:
And here's my sketch inspired by said scene: