The Greek song that is playing on Dr. Thanapapalous's speaker (apparently titled "Isaras apo tin Kriti") during Larry's first visit, is based on "Frolic", the theme tune of the show. It, along with the rebetiko tune playing during Larry's second visit at the very end, is written and performed by Billy Sullivan.
The song performed by Dylan O'Brien and the Entrails is "Peaches", a 1995 song by The Presidents of the United States of America.
Lowest rated episode to date with a 7.3 rating