Nature has a lot of wonders. Some of them may take us by surprise, or even fear. Like these animals who have something to hide in their mouths. They are probably worth hiding, because they look downright creepy and mysterious. I am sure the structure of their mouths serve a good purpose, just they are not visually appealing and they are terrifying. Surely, evolution has a way of scaring us sometimes.
Take a look at this list of animals that hide something creepy in their mouths.
source: listverse.com, creepybasement.com
sources: www.wildfowl-photography.co.uk, www.vulkaner.no, listverse.com