When Barry and Eddie are at Rusty Iron Ale brewery, there is a container that says Garrick Wharf on it. Jay Garrick was the original Flash during the Golden Age of comics.
Tony Woodward is a comic book character who made his debut in Flash: Iron Heights (August 2001). He is a villain known as Girder who developed his powers after being thrown into a vat of molten metal for assaulting a female coworker. Unknowingly there was remnants of a S.T.A.R. Labs experimental liquid steel that attached to his body giving him incredible blunt force resistance and physical power.
Dr. Wells refers to Tony as "the man of steel." This, of course, is a tongue-in-cheek reference to Superman.
This is the second appearance of Professor Zoom (Reverse Flash).
Caitlin mentions she had childhood nemisis named Lexi Laroach. DC comics has a history of using double "L" names for characters such as Lex Luthor, Lois Lane, Lana Lang, Linda Lee and Lori Lemaris just to name a few.