From Red Pine’s introduction to his Collected Songs of Cold Mountain:
Despite Kuoching’s famous philosopher monks, whenever Cold Mountain visited, he preferred the company of Big Stick (Feng-kan) and Pickup (Shih-te), two men equally cloaked in obscurity. According to the few early accounts we have of him, Big Stick Suddenly appeared on day riding through the temple’s front gate on the back of a tiger. He was over six feet tall. And unlike other monks, he didn’t shave his head but let his hair hang down to his eyebrows. He took up residence in a room behind the temple library and came and went as he liked. Whenever anyone asked him about Buddhism, all he would say was, “Whatever.” Otherwise, he hulled rice during the day and chanted hymns at night.
In James Sanford’s introduction to Shi-shu in The Clouds Should Know Me By Now: Buddhist Poet Monks of China we get this extra image:
[Cold Mountain’s collected songs] also contain … two poems attributed to their somewhat reclusive fellow traveler, the Zen monk Feng-kan (perhaps best known for his habit of using a pet tiger as a naptime pillow)