10 Anime Series All Horror Fans Need To Watch
6. Parasyte -The Maxim-
Parasyte was produced in 2014, and the story centers on seventeen year old Shinichi Izumi, whose hand is taken over by a sentient alien parasite when it failed to take over his brain. The two form a symbiotic relationship, with Shinichi naming him Migi, and they fend off other parasites (who eat humans) as Shinichi is ultimately drawn into tragedy and forced to evaluate his own humanity.
Most parasites you come across in the show aren't as intelligent as Migi, so it comes as an uncomfortable surprise when a parasite who takes over the body of a school teacher comes along. She's incredibly intelligent and thinks like a scientist rather than relying on instinct like other parasites.
The only reason she leaves Shinichi alone at first is because he wasn't worth studying, so her attitude will chill you to the bone when you explore her character. Plus, Shinichi's own psychological change is pretty twisted.