Humans
You might be surprised to find yourself included on this list, especially since we are physically weaker than most of the creatures mentioned, and come unequipped with venom and poisonous appendages. However, we humans are dangerous in our own unique way. This fanger resides in our ability to think, plan, reason, and act beyond the capacity of the creatures we share this planet with. Humans are solely responsible for the invention of war and weapons, both of which have created chaos and led to the destruction of parts of our planet. We are the only animals to have ever started a world war against each other, claiming millions of lives in the process.