Gharials are related to crocodiles and alligators—a group of reptiles called crocodilians. Gharials are one of the largest crocodilians. Some weigh more than a Harley-Davidson motorcycle! Gharials are excellent swimmers, but their legs are too weak to support their enormous body on land. Instead of walking the way other crocodilians do, gharials slide on their bellies. When a male gharial is about 10 years old, a bump of cartilage starts to grow at the tip of his snout. Eventually, the bump becomes a big knob. An adult male gharial can make a buzzing noise through its knob. Gharials are the only crocodilians with these knobs, and they grow only on males.