A rhino is a massive, thick-skinned animal with one or two horns growing from its snout. The name is short for rhinoceros, which comes from Greek words meaning “nose horn.” These powerful herbivores can weigh as much as a car and stand taller than most adult humans at the shoulder.

Rhinos have lived on Earth for millions of years, but today only five species survive, all in Africa and Asia. Their horns, made of the same material as your fingernails, have unfortunately made them targets for poachers, putting several species at risk of extinction. Despite their fierce appearance, rhinos are plant-eaters who spend their days grazing on grass and browsing on shrubs.

These animals have terrible eyesight but excellent hearing and smell. A rhino might charge at something simply because it can't see well enough to know whether it's a threat. Though they look slow and clumsy, rhinos can run surprisingly fast when they need to, reaching speeds of 30 miles per hour or more.

In everyday conversation, calling someone a rhino might suggest they're tough-skinned, able to brush off criticism that would bother others. If your friend laughs off teasing that would make you cry, you might say she has a rhino's hide.