The Batman
The Man Who Would Be Bat
S1 E5:
Dr. Langstrom, a scientist in Wayne Industry's Genome Division, has been experimenting with bats, thus threatening to endanger Bruce's secret identity. But before Bruce can stop him, Dr. Langstrom gives himself the experimental serum he's been concocting and transforms into the hideous Man-Bat, before flying off to wreak havoc across Gotham!