I saw this on TV some time in the 70's (I think) on a show highlighting foreign (non-USA) film shorts. This is what I recall.
- animated short
- black and white
- no linguistic content (spoken or text)
story line: Man alone in apartment looks out at bustling city. Doesn't like what he sees. Seems upset, agitated.
Later - Still alone in apartment. Appears sullen, bigger, darker, menacing. He leaves. He kills. He grows.
Later - He has become a giant, terrorizing the city Godzilla-like. He scoops up people and eats them. He looks unsteady, disoriented. He wanders away from city, stumbles, and falls dead.
As trucks and service vehicles stream from the city towards the fresh corpse, the "camera" pulls back and we see other giant skeletal remains dotting the landscape. We realize this has happened before. In fact, maybe this is standard practice for these people: they consume the monsters they create.