Mr. Freeze (Batman Unlimited)

"I'm no fool, Penguin. You wanted to return to Gotham for one reason: to rule it. Now that I do rule it, this makes me your number one enemy."

- Freeze betraying Penguin "Croc was durable test subject. But the others? Do you have any idea how unstable they are?"

- Freeze witnessing Bane and Clayface taking the formula

Mr. Freeze is a mad scientist who has to stay in cold climates in order to survive. He usually does his experiments in the arctic where he found the Penguin, imprisoned after the first film. With nowhere else to go, Penguin regretfully stayed with Freeze, only to be treated badly by him as a roommate.

Biography
There in the arctic, an oil platform was being built there, thus invading Freeze's territory. Mr. Freeze, outraged by it, created a device that could turn any living thing into a giant monster. Freeze placed this device on an isopod and it worked. He then sent it over to the oil platform where it caused mass destruction there. But this moment did not last for long. Luckily for the workers, they had a giant laser drill that blasted the device off the isopod, reverting it back to normal. After Penguin witnessed this, he encouraged Victor to test his latest experiment on Gotham's strongest criminals. Freeze reluctantly agreed to this.

Mr. Freeze and Penguin later broke into Arkham Asylum by using a drilling machine. There, they freed Chemo, Clayface, Bane, and Killer Croc. They then escape to an underwater lair, where Victor began to experiment on Chemo, Bane, and Clayface. He used their chemical components to create a formula that he tested on Croc and Chemo, which made the both of them gigantic. He then sent the two on a rampage to freeze Gotham.

As the climate became cold enough for him to live in, Mr. Freeze removed his suit and thanked Penguin for his services. But then Freeze betrayed him by pointing his freeze ray at him, knowing that Penguin wanted the city for himself. However, Penguin revealed Bane and Clayface taking the formula before their eyes. After being double crossed, Victor had no choice but to help the heroes, in order to stop Penguin.

The formula had a negative effect on Clayface, which turned his body into lava.