The Super Friends Meet Frankenstein (S04E07)

A descendant of the infamous Dr. Frankenstein kidnaps Batman, Superman, and Wonder Woman, siphoning their abilities into his newest creature. With the heroes' powers now in the hands of this Super-Monster, it's up to Robin to take action. He absorbs the leftover powers for himself and ultimately finds a way to reinstate the Super Friends' abilities, setting the stage for a showdown against the monstrous creation.