10. Arbok
So, you're not afraid of snakes, huh? That's logical. Most snakes are not only harmless, but many are quite small. Well, what about a snake that's not only highly venomous, but also over 6 feet tall and with a larger circumference than any species of snake known to man? Large enough to swallow a human whole, Arbok can crush steel drums with its wrap and is capable of shooting venomous spikes from its enlarged mouth. Talk about staying out of the grass! Officially, Arbok is known as the cobra Pokémon, but according to its Pokedex entries, it should be known as the inevitable Pokémon. Once it fixates on its prey, it never gives up the chase. So, if you do somehow manage to escape it, you've done yourself no favours as it will track you down. As soon as you're in its cold embrace, escape is impossible. People have had few reasons to fear snakes in today's world, but throw in this monstrosity and that fear is now justified. Suddenly, those muthaf***in' snakes on that muthaf***in' plane seem dainty in comparison.