This is a notorious conversation you will have if you begin collecting venomous animals. It is a funny unspoken rule that everyone is to correct anyone who says a snake, spider, scorpion, etc. is poisonous. The correct adjective, when referring to animals that injects a toxin, is venomous. The keyword here is inject; the manner distinguishes venom from poison. Venom is injected, and a poison is inhaled or ingested. However, many animals are still categorized as poisonous because they are dangerous to eat; for example, poison dart frogs are poisonous, not venomous. So the answer is both; animals can be venomous and or poisonous; the determinant is the mode by which the toxin enters the body. Its a technicality, but most people will correct you. It is just a funny thing that we do.