Here are 5 clues:
1. He was known for his agitated brushstrokes, which reflected his own internal disturbance.
2. He was friends with Paul Gauguin.
3. The man who cared for him after he was in an insane asylum in Arles was Dr. Gachet. The artist painted a melancholic portrait of him.
4. He painted sunflowers that looked sad.
5. He cut off his ear - the beginning of his mental breakdown.
Answer: Van Gogh, Barking Dog, 1862, pencil on laid paper