In most movies, the villain isn’t really “evil” — he’s just at cross-purposes with the hero. Darth Vader does not perceive himself to be doing wrong. The queen in Aliens is protecting her brood. The shark in Jaws is, well, a shark.
The villains/monsters of most films can be found to have one or more of the following motivations:
- Self-preservation
- Propagation
- Protection of an important asset
- Hunger/Greed
- Revenge
I’ve ranked these on a scale from “least evil” to “closest to evil.”