Bosch is a criminal Malkavian artist that has become trapped in his own painting.
Bosch claims to be the real Hieronymus Bosch (although he is far too young to possibly be him) and considers the paintings done by the mortal identified under that name as plagiarism and degenerate. His works are visualizations of a person's inner fears via Dementation. Often Bosch did not limit himself to conventional painting methods, but used the victims own blood, brain mass, and other bodily excretions to paint his works.
Bosch arrived in Vienna in 1463 and continued his gruesome art for several years before the Toreador and Tremere stepped in to protect the Masquerade after inquiries made by the Alastor Nathan Mendelson. Since that time, Bosch is trapped in one of his own paintings that is exhibited in the Kunsthistorisches Museum. Despite his trapped state, his mind works to contact anyone who would free him from imprisonment.