The Dean's cowboy outfit is an almost exact replica of the one Jeff wore to the faculty Halloween party in S01E07 Introduction to Statistics (2009). prompting Jeff to ask "is that..." before the Dean interrupts him.
The song that Britta plays on her boom box became the theme song to the Fox show Brooklyn Nine-Nine (2013), which would air its pilot episode six months after this episode aired.
A photo of Shirley, Annie, Troy, and Jeff in their costumes from Annie's Halloween party from Introduction to Statistics (2009) can be seen on Shirley's fridge in the garage.
The dip that Abed brought to the party was made by Señor Kevin, which is the Mexican themed restaurant the group has visited many times.