Condiment King first appeared in 'Batman: The Animated Series' in the episode "Make Em Laugh". He has since appeared in the comic several times, was apparently beat to death by the Human Flame, and is a playable character in Lego Batman 3. As is shown here, he tells bad puns involving condiments.
When mr. Freeze tells the story of how he met his wife Nora, the plot is exactly the same as the plot to the 1998 film "you've got mail", starting Tom Hanks and Meg Ryan. As a further hint to this, clayface guesses the name "Meg Ryan" as the identity of the woman whom mr. Freeze had met online in the story.
After Clayface mistakenly thinks the silhouette of Mr. Freeze is Lady Gaga, Freeze calls out to Harley Quinn. Lady Gaga would go on to play Harley Quinn in Joker: Folie à Deux (2024)
After the Condiment King shoots mustard onto Kite Man's suit, the tour guide of the wedding venue tells Kite Man that he has "schmutz" on his shirt in a call-out to a Key & Peele skit called Flicker.