The "old song" mentioned by Batman is Sam Brown's 1990 song "April Moon".
Of the gang, only Bullwhip is named in the episode. The other members of his gang never use a name but are named in the credits.
Strangely, Knux's weapons are originally flat pistons and later appear as metal fists in the final fight scene. Then they become pistons again when Terrapin headbutts Batman and Knux clobbers Batman. They remain pistons when Kneejerk volunteers to finish off Batman. A moment later after Kneejerk's defeat, Knux has the fists again.
Bullwhips enhancement of having metal coils come out of his wrists is similar to the Marvel Comics villain Omega Red.