Do you think that media correctly protrays how monsters and aliens would act in real life?

This is a spin-off of sorts from my previous question.

If monsters (zombies, vampires, werewolves, etc.) and aliens (E.T., Klaatu, Yoda, etc.) actually existed, do you believe they would behave and/or look like they do on movies, TV shows, and comics?

You may not have actually seen or interacted with a real one, but give your own opinion as if you do know how they act. You can be as funny or serious as you want.

What are your thoughts about this? What is the most accurate interpretation you’ve seen? Which monster or alien is best portrayed?