WARNING: The following article contains spoilers for Future State: Batman/Superman #1, by Gene Luen Yang, Ben Oliver, Arif Prianto, and Tom Napolitano, on sale now.
While villains with animal nicknames are usually more Spider-Man's thing, Batman is no stranger to animalized bad guys in his rogue's gallery. In the case of Mr. Toad in Future State: Batman/Superman #1, he isn't content to be the only animal in the zoo that is Gotham City.
It begins with Superman saving a teenager attempting to jump in front of a train. After sitting down to talk, he discovers that the kid has bought something called the False Face serum, which allows the user to briefly change their face into that of an animal. The issue with it was that it had major side effects, mainly that even when not used, any sort of nervous outbreak would cause a partial transformation. Wanting to stop it at its source, Superman briefly researches the new drug and discovers its origin: Gotham.
Flying to the city, he meets up with Batman, who is having to work in the shadows even more than usual due to the enforcement of the Magistrate. He's already aware of the serum, and after the two of them interrogate a bunch of teenagers using it to avoid the Magistrate's facial recognition technology, they discover that they received the serum in Old Gotham, a whole buried beneath the new one. They find where the drug is being created, and Batman hacks into the computer while Superman fends of half-human, half-animal hybrids.
It's during these scuffles that Superman encounters Mr. Toad, aptly named due to the fact he has the head of such an amphibian. He claims to be the cousin of the original Mr. Toad, and that he is the current leader of the False Face Society. Originally founded by the Joker, the Society was formed as a sort of competition to see who could get the most loot from crimes, all while wearing masks. After that, the Society became the gang of Black Mask, with his goons all wearing face coverings from his large collection.
Under Mr. Toad, however, there seems to be a much more noble cause for the group, using it to fight against the oppression of the Magistrate. Superman then explains he encountered his daughter earlier, and that the side effects could potentially be very dangerous to her. He sympathizes with Toad and his cause, but believes there must be a better way. Toad initially looks like he'll surrender, but instead stabs Superman with a kryptonite knife. The briefly-mentioned cousin of the current Mr. Toad has a very limited comic history, appearing in a single issue before being killed off, but the current Toad's interest in human-animal experimentation does link to one of his old colleagues: Professor Pyg. Lazlo Valentine is a scientist and surgeon who suffered a schizophrenic breakdown, leading him to disconnect from reality. Donning a pig mask, he became obsessed with perfection, kidnapping people and operating on them to create what he calls "Dollatrons."
While often fixated on improving the human form, he has been known to fuse people with animals before, calling them "Farm-Hands", and using them for his bidding. We've already seen Toad use his serum on potentially innocent people for super-powered bodyguards, so who's to say he didn't pick that up from Lazlo, who has had to deal with his cousin in the past. It's already been revealed that Professor Pyg is active in this "Future State" version of Gotham, so what's to say he isn't also involved in this grotesque experimentation with Mr. Toad. With Superman incapacitated, it will be up to Batman to take on this amphibian adversary, and potentially the swine surgeon as well.