Batman Unlimited: Mechs vs. Mutants

Damian, the new Robin, is upset by his failure at trying to stop the Joker the previous evening and being humiliated after he fell off a building and had to be saved by Batman, which was caught by a video blogger and posted on the Internet. Alfred Pennyworth tries to assure him that he is still learning, though Damian wishes he could talk to someone else who has been through the Robin training as Red Robin is away with his team. Batman arrives as Damian is studying Batman's enemies, and comes across the Penguin, who he has never met.

In the Arctic, Penguin, who has been in exile following the events of Batman Unlimited: Animal Instincts, is depressed at having lost everything. His only companions are Mr. Freeze and Buzz, a penguin who seems to understand Oswald's predicament. Freeze tries to repel a group of oil drillers near his ice cave, using one of his inventions to mutate an isopod into a gigantic monster to attack them. The Drillers use a new laser-drilling sled to attack the monster, and in the process, damages Freeze's invention, turning the monster back into an isopod, which causes Freeze to depart in anger. Penguin sees a way to capitalize on this, and encourages Freeze to take him back to Gotham City where he assures Freeze the means to achieve his goals.

Back in Gotham, Bruce and Damian are attending the new Technology Showcase at Wayne Tower where Dr. Kirk Langstrom is unveiling a new single-operator drilling mech which can melt rock in order to mine more easily. Bruce receives a call from Alfred that someone is attempting to break into Arkham Asylum. Oliver Queen, who is present at the showcase, sees them leave and follows them.

At Arkham, Penguin and Freeze drill into the asylum and freeze the guards, then bypass several inmates such as Cheetah, Hush, Mad Hatter, and Two-Face, before freeing Bane, Chemo, Killer Croc and Clayface. They also pass Joker on their way out who is upset that Penguin refuses to free him. Batman, Robin, and Green Arrow arrive and battle the villains, only to have Freeze and Bane successfully escape with their allies.

At the Batcave, Batman tries to figure out what they're up to, but comes up empty while comparing MO's and criminal histories. Robin figures out that there is a pattern based on Bane, Clayface, and Chemo's chemically altered DNA, and Killer Croc's strong constitution would make him an ideal test subject. Batman uses this info to track down the forced chemical mixture through a croma-spectral scanner. Meanwhile, in their undersea cave hideout, Freeze uses Bane's super-steroid Venom, Clayface's shape-shifting protoplasm, and Chemo's toxic waste to create a serum to transform Killer Croc into a gigantic ice-spewing monster. He injects the same serum into Chemo, who works with Croc to freeze Gotham.

While on their way to Freeze's hideout, Batman and Robin see the mutated supervillains, and attempt to stop them with the Batmobile and Batplane, but are unsuccessful. The Flash, Nightwing and Green Arrow are saving citizens as best they can while Croc attacks the GCPD headquarters. Despite their best efforts, the police can't stop the gigantic Killer Croc. Meanwhile, Freeze and Penguin turn on each other, both wanting to eliminate their rivals for control of Gotham. However, Penguin's henchbird Buzz has stolen samples of Freeze's formula, which Bane and Clayface use to turn themselves into monsters. Despite his warning about the effects of the serum on the other two, Freeze is easily dispatched and Penguin sends Bane and Clayface after Batman. Bane, however, has a score to settle with Croc, who sold him out to the Gotham Police, and attacks him. Clayface locates Batman and Robin and attacks them, only to have Freeze's formula alter his body, turning him into a giant lava monster.

Batman gives the key to the Batmobile to Robin and tells him to distract Lava-Clayface, while he goes to Wayne Enterprises to get a special project Langstrom has been working on: a Bat-Mech the same size as Croc and the others. Green Arrows arrives and reveals that he had Langstrom build an Arrow-Mech for him, which Langstrom states that he received a contract from Queen Industries for research and development. Batman goes to deal with Croc and Bane, while Green Arrow deals with Chemo. Batman then sends Langstrom to go help Robin, who was unable to stop Lava-Clayface, who then, with Flash and Nightwing, build a special laser cannon to stop Lava-Clayface.

The two heroes engage the trio of monsters, Batman quickly defeats Killer Croc, who with the serum's mutational effects wear off, shrinking Croc back to his normal size and state, and while Green Arrow manages to destroy Chemo's ice blaster, he barely holds his own against Chemo himself. Meanwhile, Freeze, guilty over his manipulation and betrayal by Penguin, aids the heroes in perfecting their cannon to use against Lava-Clayface. After Batman defeats Bane, he goes to help Green Arrow battle Chemo, who causes a Queen Industries build to collapse on him, damaging the Arrow-Mech. Working together, the pair crack Chemo's shell open, allowing to drain the chemicals out of him and shrink him back to normal. Freeze, though injured by Lava-Clayface, is able to get the freeze ray to work and freezes Lava-Clayface solid. With Croc and Chemo defeated and back to normal, Gotham's climate returns to normal. Noticing this, Penguin and Buzz try to escape, but are captured by the Bat-Mech.

Penguin and his cohorts are arrested, along with Freeze who admitted that he was responsible for Gotham's icy conditions, but will get a trial for his involvement. Penguin and the others are sent back to Arkham, while Buzz the penguin is sent to a zoo, meeting a female penguin who falls in love with him. In Arkham Asylum, Joker gets even with Penguin for leaving him in Arkham instead of freeing him. Langstrom starts to repair the Mechs and upgrade them in case of another giant monster attack.

The other heroes leave the Batcave and Batman congratulates Robin on doing a good job. Damian feels better in his role as Robin than he did before, the two then head to the training room, with Alfred on watch duty. Meanwhile, Clayface escapes his ice prison and slinks into the sewers.

• Roger Craig Smith as Batman/Bruce Wayne
• Oded Fehr as Mr. Freeze
• Lucien Dodge as Robin/Damian Wayne[6]
• Dana Snyder as Penguin, Buzz
• Chris Diamantopoulos as Green Arrow/Oliver Queen, Cobblepot Guard (uncredited)
• Phil LaMarr as Dr. Kirk Langstrom, Arkham Asylum Guard (uncredited)
• Will Friedle as Nightwing/Dick Grayson
• Charlie Schlatter as The Flash/Barry Allen
• Carlos Alazraqui as Bane
• John DiMaggio as Killer Croc, General Sam Lane
• Dave B. Mitchell as Clayface, Hush (uncredited), Chemo (uncredited)
• Troy Baker as Joker, Two-Face
• Alastair Duncan as Alfred Pennyworth, Mad Hatter (uncredited)
• Richard Epcar as Commissioner James Gordon

• Batman Unlimited: Mechs vs. Mutants at IMDb