After terminating his relationship with Amy, who was not his girlfriend at the time, in season 4, episode 3, "The Zazzy Substitution", Sheldon began to collect cats as an affection substitution though he denied the connection. His first cat was named Dr. Robert Oppenheimer, whom Sheldon carried around with him including into the Caltech cafeteria. Later Leonard comes home and finds the living room full of cats. Sheldon explains that Dr. Robert Oppenheimer was lonely. “So you decided to get the whole Manhattan Project?” asked an exasperated Leonard. He named his other cats Enrico Fermi, Richard Feynman, Edward Teller, Otto Frisch, and Zazzles. The last cat was going to be named Hermann von Helmholtz, but Sheldon found him so zazzy that he named him Zazzles. Leonard again tried to tell Sheld