The Poodle Shark is so called because of the round knobs of cartilage that were found at the top and bottom of its tail, on the top of its dorsal fin, and on the ends of its pectoral fins. These round protuberances hindered the shark’s passage through the water, slowing its progress by about 20% due to the resistance of the water against the knobs.
Where the knobs did come in useful was during a feeding frenzy. Most sharks attack with their teeth, which are their only weapon. Poodle sharks are different. Not only do they have sharp teeth, they are also able to attack with their tail and fins, which are very flexible. A poodle shark is able to swish its tail and hit its competitors in the face with its tail knobs, as well as hitting other sharks with the pectoral knobs and biting yet more sharks with its teeth.
Julian Worker Fiction Writing 