In the 12th century the Chinese master Kakuan drew the 10 bulls, basing them on earlier Taoist drawings. The earlier drawings had only 8 bulls, with the eighth representing the final stage of enlightenment. Kakuan went beyond this, illustrating that the moment of enlightenment is merely a beginning.
These bulls were drawn by the Kyoto woodblock artist Tomikichiro Tokuriki, and published in Zen Flesh, Zen Bones by Paul Reps.