Fulmar (Europe, North America)2
If there were awards for the most disgusting animal, the Fulmar would probably win big. The Fulmar looks like a seagull and its name means "foul-gull." These icky birds defend themselves by projectile vomiting at their would-be attackers. They can hurl up to five feet at other birds that attack them. The puke isn't just disgusting, it's also acidic, so it can eat through the weatherproof coating on the enemy bird's feathers. Eeeeww.
Tarantula (U.S.A., South America)
Most people know they shouldn't touch a wild Tarantula but it's probably not a good idea to get too close to them either. When a Tarantula feels threatened it uses its feet to grab hairs from its back and then throws them at its opponent. They are barbed, kind of like fishhooks, so they're hard to get rid of and they really sting when they get in the attacker's eyes. Ouch. Tarantulas need this kind of protection cuz they're pretty vulnerable. If a Tarantula falls it'll shatter and die.
Mimic Octopus (Ocean near Indonesia)
The Mimic Octopus is the real master of disguise. It can shape-shift into scarier creatures so predators don't eat it. The Mimic Octopus can change its color and shape to imitate a venomous Lionfish, a Mantis Shrimp, a mass of deadly Sea Snakes or a bunch of other sea animals.