Assassin bugs are nasty little crawlers, that could easily take roles as perpetrators in series like Hannibal or True Detective. They lie in wait for their prey and when it is there, they stab it with multiple stabs with their sharp mouthparts. Then they inject enzymes dissolving the prey from the inside to suck it out afterwards. This gave them the name Assassin Bug in the English language, as they often assassinate their victims sneakily. But the not enough. Some predatory bug species (A. Petax) carry the shells of their killed prey animals as a kind of armor. Maybe to proudly show their trophies all over the world? Or to find the recognition, every serial killer seeks to get
There are also -what people call- “Shrike” birds appearing somewhat suspect, if you take a look at their approach in more detail. The “Shrike” impale their prey on thorns or spines in hedges to keep it for later or to kill them more effectively. Depending on the size of the “Strangler” the prey ranges from insects to mice and lizards. Gradually, there might be a whole morgue emerges, which the Strangler presents to the world. As if it wanted to say: “See my work ?!”
There are definitely animals whose behavior is morbid enough to give us nightmares.
Copyright and Source: http://www.iflscience.com/plants-and-animals/most-horrifying-and-awesome-creepy-crawlies-world (Orion Mystery, via Wikimedia Commons), http://orionmystery.blogspot.de/