1) Prairie Dogs - You never know when they're going to pop their little heads out of the ground and cause you to trip. They're cunning in that way.
2) Turtles - Not only do some of them like to snap like an old man in a long deli line, but they especially don't like it when you try to use them as a football.
3) Cows - They have four stomachs so they could easily eat you and three of your friends/witnesses. That's most likely the reason why so many people are still listed as "missing" and cows are not seen as likely suspects.
4) Birds - If the movie The Birds was not enough to make you aware of just how dangerous birds are, then the movie Black Swan should have removed any doubt (the movie Black Swan may not kill you per se, but it may make you wish you were dead by the time you sit through the whole movie).
5) Kangaroos - Like cows, Kangaroos come equipped with the ability to hide their crimes but instead of using their stomach they use their pouches. Most likely you will have been kicked to death prior to suffocating in their pouch though.
6) Cats - There's a reason most people don't mess with cats - they have 9 lives and very sharp claws. They're always lurking in the dark and when they're not hiding they're flexing their legs as if to say "I'm flexible, and I will claw you to death."
7) Deer - Deer are crazy. Straight up loco. They have no fear of death and you don't want to mess with an animal that doesn't fear death. They may look sweet and innocent, but you won't think that much longer when you see one in the middle of the road just daring you to hit them. Certifiably loco.