The movie the penguin is watching at the beginning has a Bruce Timm style animation to it.
First appearance of Killer Moth (voiced by Jeff Bennett) in "The Batman".
First meeting between Batgirl and Robin in "The Batman".
The movie the Penguin is watching at the beginning is a nod to The A-Team (2010), and the team leader's motto "A blueprint for success" is basically Liam Neeson "I love it when a plan comes together".