Professor Cavanaugh is the former mentor of Dr. Laszlo Kreizler when he was a student at Harvard University.
He's a guest starring character portrayed by David Warner.
Around 1877, Professor Cavanaugh received a visit from Laszlo Kreizler during his first day on campus at Harvard. The student was still unsure about his own future and asked Cavanaugh take his class. Professor Cavanaugh allowed him to attend his Introduction to Ornithology class and assigned Kreizler a preserved specimen to study, known as Hildebrandt's starling. Laszlo looked the bird over, after a short time, returned and gave his teacher a few sentences describing it. Unsatisfied with it, Professor Cavanaugh told him to look at the bird again. After Laszlo did as instructed, he returned with a 4-page essay. But again, Professor Cavanaugh sent him away. After three more days looking at that Starling, it was beginning to molt and Laszlo realized he was finally starting to see "his bird," namely his interest in pathological anatomy. 
Professor Cavanaugh agreed to meet his former student Laszlo Kreizler in a literary parlor, where the two recalled their first meeting. Professor Cavanaugh said he had followed the career of his former pupil with grateful enthusiasm and pride, and asked him what he could do for him. Dr. Kreizler said to be at an impasse and he hoped he could get a guide from his former mentor. Professor Cavanaugh, then, reminded Dr. Kreizler of the experiment with the Hildebrandt's starling of when he was a student at Harvard. The older man was implying that Laszlo had to change his perspective, freeing himself of involuntary preconceptions that blurred his vision. The two parted with affection and mutual respect. 
Appearance and Personality Edit
Professor Cavanaugh is an old, tall and thin man in his elder, with sparse white hair, a hooked nose, and blue eyes framed by small, round spectacles. As a University Professor, it is fair to assume Cavanaugh is an influential expert in his field of study. He is a calm and composed man, as well as an excellent teacher who lets his students reach their full potential according to their abilities. In fact, his teaching method wasn't a matter of what his students learned in class, but how they learned it, as he explained to Dr. Kreizler.
- Professor Cavanaugh: "I remember your first day on campus. You came to me and you asked to take my class.You were unsure about your future, you said, and an Introduction to Ornithology led you down a path that you didn't even know you would take."
- Professor Cavanaugh: "It wasn't what you learned in class, Laszlo. It's how you learned it."
- Dr. Kreizler: "Much to my dismay, theory seems to have replaced pragmatism. Can you suggest to me what I might do?"
- Professor Cavanaugh: "Look at your 'bird,' Laszlo. Look at your 'bird.' "
- Although Professor Cavanaugh doesn't feature in the novel by Caleb Carr, he could have replaced the in-universe depiction of William James, a famous psychologist who taught Dr. Kreizler, John Moore, and Theodore Roosevelt in 1877 at Harvard. Contrary to the teacher-student relationship between Cavanaugh and Kreizler, that of Kreizler and Williams was more heated.
- Ep. 5: Hildebrandt’s Starling