Bruce Campbell's favorite episode of the entire show.
All three male leads in this episode, Bruce Campbell (Ash), Ray Santiago (Pablo), and Joel Tobeck (Baal/Doctor Peacock), are left-handed.
When Ash becomes violent, Doctor Peacock injected him with a hypodermic needle filled with a sedative commonly used in actual psychiatric wards, called "Midazolam". Most psychiatric wards in regular hospitals use that or something similar. Patients commonly refer to it as "the Happy Needle" for the intense feeling of relaxation (not to be mistaken with the feeling of being stoned such as when one is injected with Morphine) before the sedative knocks them out completely within a few short minutes. Though back in olden times it was the direct go-to method for calming down violent or agitated patients, nowadays psychiatric nurses and doctors prefer to leave that as a last resort, though it is still used when nothing else works.
Ash (Bruce Campbell) makes a dirty joke to Ruby (Lucy Lawless) about playing nurse and patient, making a reference to Nurse Ratched (from Ratched, 2020 and One Flew Over the Cuckoo's Nest, 1975)
At 18 minutes Kelly asks Ash "What the fraggle rock is that?". Fraggle rock was a TV series that ran 1983-1989 starring Muppets much like Ash's hand puppet.