The Hostile Hospital: Part Two - S2-E8
Trivia: When Olaf catches Klaus in the corridor while Klaus and Sunny are disguised as a doctor, he tells Klaus that he looks terribly young to be a doctor. This is a reference to the fact that Neil Patrick Harris, who plays Count Olaf, played the role of Doogie Howser, a teenage doctor, in "Doogie Howser: MD" in the late 80s to early 90s.
The Hostile Hospital: Part Two - S2-E8
Trivia: Right before Klaus is to perform surgery on Violet, a diagram is pulled down showing an anatomical view of a head, including the brain. If you look closely at the portions of the face that are visible, the head is actually Barry Sonnenfeld - whom produced and co-directed this series, in addition to co-producing the prior 2004 film adaptation.