10 Terrifying Anime Villains That Gave You Nightmares

John Carpenter would be proud.

These monstrosities from the criminally underrated Parasyte: The Maxim are the thing of nightmares. Much like the alien from The Thing, anyone could be harboring one of these vicious killing machines behind their seemingly human exterior. While dead eyes and a lack of emotion might be a giveaway, no one would know that unless they were looking for it. They are the ultimate predators.

The opening scene of the series says it all. An unsuspecting woman stares her former husband in the face as his head opens up revealing a cornucopia of inhuman terror right before biting her head clean off. This immediately establishes just how much of a brutal, vicious threat these things are.

Luckily for series protagonist Shinichi he was able to trap his parasite, Migi, in his right hand before it took him over completely, merging with it in a partnership based around a mutual interest in survival. However, even then Migi makes it clear that the moment the opportunity presents itself he'll kill his unwilling partner and move on to better things.

Throughout the series, multiple other unique parasites become more prominent in the story. Some even border on the edge of obtaining humanity. It's this complex idea of what it means to be human at the heart of the series that adds to making the parasites so unnerving. If a creature such as them can attain humanity, what does that say about humanity?