Paul Klee was a Swiss-German artist who is best known for his abstract art. He was also a prolific painter, printmaker, and draftsman. He was a member of the Blaue Reiter group of artists and is considered one of the most important figures in modern art. Klee's work was influenced by Expressionism, Cubism, and Surrealism. He was also a pioneer of modern art techniques such as watercolor and oil painting. Klee's works often featured whimsical elements, such as birds, animals, and plants. His most famous painting, Twittering Machine, is an example of his unique style.