* Defense: A porcupine is known for its defensive spines. The opposite could be an animal that is completely defenseless, like a sloth, or an animal that relies on offense like a lion.
* Diet: Porcupines are herbivores. An opposite could be a carnivore like a wolf or a highly specialized insectivore like an anteater.
* Habitat: Porcupines are found in forests and woodlands. The opposite could be a desert animal like a fennec fox or an aquatic animal like a dolphin.
It's important to remember that "opposite" is a subjective concept, and there's no single "opposite" animal to a porcupine.