Their bristly spikes make them really hard to get to.
I think it serves as they're protection against predators.
Porcupines have quills which look like needles on their backs. These protect the porcupine against predators and come contain a poison.
It ducts its head to protect its unprotected face and underside, positions itself to where its tail is facing the foe, and backs itself into it. The quills stick in, and are hard to get out. If the quills get in the mouth, the offender might not be able to eat.
Sharp body to protect themselves
Rockhoppers are very small animals. They cannot protect themselves against predators very well because of this, so they are easy prey.
Antelopes live together to protect themselves against predators.
Yes either to take down prey or fend off predators
Hopefully the individual themselves. If not, there are laws that protect potential victims against sexual predators.
predators
A rhinos large size is its first line if defense. Secondly, they are covered in hide that is so tough it is almost like armor against predators. Third, they have horns and charge any potential predators. They are formidable enough that adults don't have any natural predators. They cannot protect themselves against humans, though.
Scorpions protect themselves by having a hard exoskeleton that serves as a physical barrier against predators. They also have venomous stingers that they use for defense when threatened. Additionally, scorpions are nocturnal animals, which helps them avoid many predators that are active during the day.
To protect themselves from predators.