There are several 'Wizard of Oz' Easter eggs in the episode. Lahr's name is the same as Cowardly Lion actor Bert Lahr, and the episode revolves around courage, which is what Lahr's character the Cowardly Lion wanted. Lahr's assistant is named Dorothy and her partner's last name is Gale: in 'Wizard of Oz' the main character is Dorothy Gale. Finally, Lahr's partner's first name is Frank. 'Wizard of Oz' was written by L. Frank Baum.
Vita, the Kryptonian witch whom Kara and Lena consult for information on the totems, was one of the priestesses who created Reign and the other World Killers in Season 3.
Alex's line "Sweet, another dragon" is likely referring to Kara having to deal with Spike, the pet lizard of a National City resident who has been turned into a dragon twice before, in "Call to Action (2018)" and "Crisis on Infinite Earths: Part One (2019)".