It's exactly the uncanny valley effect of being human-like. Consider sci-fi utility robots like this, which most people don't find "creepy" (maybe intimidating,

It's exactly the uncanny valley effect of being human-like. Consider sci-fi utility robots like this, which most people don't find "creepy" (maybe intimidating, but that's different): https://www.youtube.com/watch?v=_VkOlvXTvLI https://www.youtube.com/watch?v=_VkOlvXTvLI Meanwhile humanoids are the stuff of actual horror movies: https://www.youtube.com/watch?v=1c7XccFwJrQ https://www.youtube.com/watch?v=1c7XccFwJrQ I'd predict that a crab-like or dog-like robot would be better accepted for home robotics for this reason. We will not want them to look like us. The same is true for aliens. A giant bug, octopus, or quadruped is far less scary than something vaguely humanoid. Sci-fi horror aliens like the xenomorph or the "greys" hit the uncanny valley in various ways.