2. Killer Croc
If you’re looking at the image above and thinking to yourself, “They’ll NEVER be able to do that on a TV budget,” then you’re probably right.
However, Waylon Jones actually started off with a skin condition that simply resulted in scales appearing over parts of his body. After filing down his teeth so they resembled that of a crocodile, he fought alligators for a living as part of a circus before finding his way to Gotham City and turning to a life of crime.
Many years later, his disease would worsen and a virus caused him to become more monster-like than ever before. It would make perfect sense for Gotham to feature a younger version the villain before his transformation into the beast above, and focusing on only a slight deformed version would be a perfect way of introducing Killer Croc without the need for ridiculously expensive CGI.