There are many references of Superman. Some are obvious, but some are very hidden.
On "Bat In A Belfry", it is mentioned that Detective Ellen Yin is from Metropolis, the fictional city in the Superman mythos.
On "The Big Heat", after Firefly blows... more
The first episode of The Batman, "Bats in the Belfry," shows a sequence in Arkham from a semi over-head view of celldoors in the asylum opening. On the right, toward the bottom, a blond man emerges from a cell; this is Bruce Timm, producer of the previous... more
The voice of the mayor of Gotham city is non other than Adam West, the Batman in the old show.