They feed on a variety of food.  Some of that being small fish, sea urchins, squid, anemones, mollusks, and crabs.  Because they are slow moving they feed at night on the non-active animals.  An example of this would be a Blacksmith (Chromis punctipinnis), which sleeps at night and makes it easier for the shark to grab.  An interesting fact is that if their diet is made up of mostly purple urchins (Strongylocentrotus purpuratus) that their spines may turn purple.  The horn shark has very distinguishing characteristics such as the horns located just before the dorsal fins.  These are used as protection from possible predators.  If a predator were to try swallowing the shark it would almost immediately feel the sharp spins and spit it out.  Even the newly hatched baby horn sharks are equipped with this defense.  The sharks has even been said to resemble a pig or a frog.  They grow to be between the size of 2 to 3 feet in length, and can live up to 25 years, but may live as long as 50 years old.  They are a fairly docile shark and will only attemp to bite if provoked.  The horn shark is not on the threatened list.  One can see a horn shark in a Southern California Aquarium.