When in disguise as Doctor Faustus, Klaus claims he studied at Oxford. In reality, Louis Hynes is from Oxford, and the accent he used as a disguise is his own accent just made to sound as if he was older
The diagram of the human head that Olaf and Esmé refer to before the operation is an illustration of the head of Barry Sonnenfeld, the show's executive producer and director of 8 episodes thus far. Incidentally, the diagram labels areas of the brain, listed as: Happiness, Reasoning, Brilliance, Ego, Anxiety, Self-Loathing, Adolescent Child-like Behavior, and Overthinking.
Next to Violet's alias on the patient list, it states that she's been admitted for a runny nose.
Henchperson of Indeterminate Gender reads a fictional romance novel by Joe Tracz. Joe Tracz is one of the show's editors.
Klaus's character Dr. Faustus is named after The Tragical History of the Life and Death of Doctor Faustus by Christopher Marlowe.