Father and daughter Joe Walsh and Lucy Walsh appear together: Joe Walsh as himself and Lucy Walsh as Sgt. Natalie Whitfield.
The Joe Walsh lyric Morgan quotes at the end is from the song "Life's Been Good," the final track on Walsh's 1978 album "But Seriously, Folks..."
The medical examiner, Cranston, remembers Spencer and greets him warmly when Reid and Lewis arrive at the morgue. They tell Lewis that they worked together on a case four years before, and Cranston says, "The tornado guy; that was one for the books!" He is referencing unsub Travis James from There's No Place Like Home (2011).
It's occasionally mentioned that Rossi is friends with Ringo Starr. In 2008, Joe Walsh became Starr's brother-in-law when he married Marjorie Bach, the younger sister of Starr's wife Barbara.
Aisha Tyler contributes to the discussion of the case on the jet about the mythical character the Sandman. Of course, this can be seen as ironic since she plays Mother Nature who rules over the mythical characters (Easter Bunny, Sandman, Father Time, Tooth Fairy, and Cupid) in both The Santa Clause 2 (2002) and The Santa Clause 3: The Escape Clause (2006).