Monsters

Monster is a generic term for a mythological creature. These are often based off of animals or parts of their bodies resemble animal features, however not all monsters have these traits. Most often "monster" is used for a solid-based being, as opposed to a spirit. But it's not unknown, and the phrase "monstrous spirit" is perfectly understandable. A "dog monster" would indicate a monster that's based off of a dog, and a "plane monster" would indicate a monster based off of an airplane, though most monsters aren't considered to be technological, though they may be monstrous. "Human monster" is understood, but isn't actually correct linguistic wise. Sometimes monsters that are based off of something don't need their animal prefix attached during their discussion. Hence, they're understood to be not real or fantasical variants of the creature's they are based upon. This is one of the reasons why I separate the proper English noun for an animal from it's scientific name- a dog monster is still somewhat read as a dog, even if not a real one. Thus an unreal monster is a dog, as is it's real world counterpart.
Monsters are often aggressive towards humans, sometimes without a specific cause for destruction. In stories the monster trope may be subverted to display a non-human creature that, aggressive or not, is not actually that bad of a living being, or at least isn't soul-less. Undertale is one example of this subversion. Monsters are celebrated during Halloween, which is why I'm writing this article.