porcupine

/ˈpɔːrkjəpaɪn/
noun
  1. A medium-sized animal with a body covered in long, sharp spines (quills) that it raises to defend itself.
    • We saw a porcupine waddling across the hiking trail at dusk.
    • My dog got too close to a porcupine and ended up with a nose full of quills.
    • The porcupine uses its quills to protect itself from predators like foxes and coyotes.
  2. A person who is difficult to approach or interact with, often because they are defensive or prickly in manner.
    • Our new manager is a bit of a porcupine — every suggestion is met with criticism.
    • He acts like a porcupine when anyone tries to give him advice.
    • After the argument, she became a porcupine, snapping at everyone who came near.