ambient arthropod
Ambient arthropods are small subtle arthropods found off in the background of an image. Removing an ambient arthropod would do little to change the feel of an image. They're mostly just there to make the world feel a little more alive. If the main character is interacting with or touching the arthropod in question, it's probably not an ambient arthropod. Unless a non-ambient arthropod is also depicted, arthropod…
