Intravenous Injection of Chemotherapy. It is very common for chemotherapy medications to be injected into a vein, or intravenously. In many cases, a nurse or doctor will insert a needle into your vein, often in your hand or arm, and the chemotherapy will be given through there.
2. Poison Dart Frog. Of all the poisonous animals in the world, these are probably the easiest to spot due to their extremely bright colors, including yellow, blue, green, & red. These frogs don't actually inject their poison through their mouth; they do it through their skin.
Snakes are considered to be the deadliest animal on earth due to the high number of people that are killed each year from snakebites. The Asian Cobra is notorious for killing the most, due to its aggressive behavior and lack of fear towards humans.