Venom/ˈvenəm/ Definition 1 of 2Pro Tip 1/3Animal Source Venom is always related to an animal origin; plants can be toxic but not venomous. Biologists are studying the venom of different sea creatures. Pro Tip 2/3Purposeful Use Animals use venom to defend themselves or to catch food, not accidentally. The platypus, surprisingly, produces venom. Pro Tip 3/3Not Always Deadly Some venoms aren't deadly to humans and can cause mild reactions. Bee venom causes pain and swelling but is seldom fatal.