Have you ever made sketches on a piece of paper or in a notebook? The artist who created this drawing made a huge number of sketches in his lifetime. He was so famous that after his death his notebooks and drawings were studied and copied by other artists. More than 4,000 of his drawings still exist. His name was Leonardo da Vinci, and he lived from 1452 to 1519.

Da Vinci often sketched pictures of human figures, animals, and scientific and engineering ideas he wanted to explore. Sometimes he made many different drawings on a single page as new ideas came into his head. These particular drawings are nicknamed "brainstorm sheets."

Da Vinci was also interested in the wide range of expressions you see on a person's face. He liked people who looked peculiar. If he happened to see someone on the street who was out of the ordinary, Da Vinci would sometimes follow that person around for a whole day and then go home and draw a portrait from memory.

The strange-looking man shown here is from a series of drawings Da Vinci made called visi mostruosi in Italian, which means "monstrous faces." The laughing man's features are certainly out of the ordinary—he has a very large nose and chin, out-of-control hair, and pointy teeth.