The cats of Louis Wain
Louis Wain started to draw cats to amuse his wife who had cancer, then he became popular for his cats drawings and postcards.
At first, he was drawing cats doing stuff human beings do, then his drawings evolved as his schizophrenia was getting worst. His cats became more and more abstract and tortured.
His work is often displayed as an example of schizophrenic artist. Via Dangerous minds.