Clayface II is gray here rather than the pinkish hue he had in his debut episode.
The jet pack Robin gets in this episode was first seen on the Robin action figure released by Mattel Toys early 2007.
Dana Delany and Clancy Brown reprise their roles from the 90's Superman: The Animated Series, while George Newbern reprises his from Justice League.
(After Superman runs into Robin while he's flying on his jetpack)
Robin: I've got an idea for the next prototype: barf bags!
Metallo: Lookin' a little green, Supes. Me, I love Kryptonite; Can't get enough. But I guess one man's power source is another man's poison.
Jimmy Olsen: (about Superman: Wait'll they see him, Ms. Lane. The roof's gonna come off the building.
Dick: Fan boy.
Jimmy Olsen: What are you, un-American? He's Superman!
Dick: Well, we have our own hero.
Jimmy Olsen: The Bat? He's okay, if you like the circus.
Batman: (referring to Superman) He's not much for conversation, is he?
Robin: Like you should talk.
Barbara Gordon/Batgirl does not appear in this episode.
Wallace Langham does not reprise his role of Clayface (Basil Karlo). Instead, Lex Lang voices him here but makes his grunt sounds.
Bane, Black Mask (with Number One and his organization), Clayface (Basil Karlo), Mr. Freeze, and Poison Ivy return; however, only Black Mask and Clayface II speak, and Clayface II now has a different voice actor.
Superman, Lois Lane, Jimmy Olsen, Lex Luthor, Metallo, Mercy Graves, and Mayor Hamilton Hill are introduced.
Lex Luthor: Bow to me.
When Lex Luthor says this, it's reminiscent of General Zod's line to Superman in Superman II.
When Lex Luthor uses Poison Ivy's spores on Superman he mentions that he laced the spores with Kryptonite. In the graphic novel Batman: Hush, Poison Ivy combines synthetic Kryptonite with her spores and uses them to control Superman.
Robin makes a reference to a famous Terminator 2 movie line/quote ("Hasta la vista, baby.") when driving away on his motorcycle with the green kryptonite from Metallo.