OK, I will rephrase my question. What is most dangerous on Earth? Now, that too is way too broad of a question. The answer to this second question could be war, radiation dangers, the freeways, the jungles, the deserts, nuclear war, etc., or this:
Well, let's try again. What is the most dangerous creature on Earth? Well, that narrows it down some, but not quite enough. An answer to that question, and the one at the top of the list, would be mankind. Other answers could range from the small (bacteria, microbes, etc.) to the medium sized (snakes, bees, scorpions, rabid animals, etc.) to large sized (rhinos, elephants, tigers, lions, mean bulls, a sumo wrestler, etc.).
Well, I don't think any of the above is the answer. There are a lot of things that are venomous and/or poisonous. Most all venomous things are living creatures that inject their venom into their victims. Poisonous things can transfer their poison by touch or if you eat them. My choice of most dangerous fits the last kind.
Yep, it is a pretty little frog that comes in a lot of different colors, a Poison Dart Frog that lives in Central and South America. Isn't it cute? Just don't ever pick it up with your bare hands. It is not venomous, but it is very, very poisonous. Its skin is covered by a very deadly poison, an alkaloid toxin. that prevents the nerves of what ever it bites from transmitting signals to its muscles. That leaves the muscles in an inactive state of contraction, thus stopping the heart from beating. Some native people in areas where this frog is found, use its poison on darts and/or arrows. I guess that would keep a wounded animal from escaping. This cute frog has enough venom to kill about 10,000 mice and from 10 to 20 humans. This puts a different meaning to the phrase (you can look, but don't touch). Now, be careful what you pick up and have a great day, you hear?