Defence against predators
Fight back (retaliation or fighting defence): there are a very large number of animal weapons, and many are used for face-to-face fighting. Bombardier beetles squirt hot poisonous liquid at attackers. Large herbivores often carry weapons: Triceratops, Iguanodon, elephants, deer, Rhinoceros, Hippopotamus. Almost always the weapons are used for several functions, not just fighting predators.