|Batman Unlimited: Monster Mayhem|
|Directed by||Butch Lukic|
|Screenplay by||Heath Corson|
|Produced by||Butch Lukic|
|Starring||Roger Craig Smith|
Brian T. Delaney
Dave B. Mitchell
|Edited by||Bruce A. King|
|Music by||Kevin Riepl|
|Distributed by||Warner Home Video|
Batman Unlimited: Monster Mayhem is a direct-to-video animated superhero film and the second entry in the Batman Unlimited series. It was released on August 18, 2015 on Blu-ray, DVD and Digital HD. It is a sequel to Batman Unlimited: Animal Instincts.
The film opens with Solomon Grundy and Silver Banshee escaping from Arkham Asylum on Halloween Night. They hijack a civilian's car and get chased by cops. They lose them, but Nightwing (Dick Grayson) sees them when Green Arrow appears. Silver Banshee sees them and attacks with her sonic screams while they dodge. Batman and Red Robin drive up behind them in the Batmobile, but Silver Banshee screams in the tunnel to make rubble fall and block their path while Nightwing and Green Arrow follow them on their motorcycles. Scarecrow throws fear gas balls in Nightwing's and Green Arrow's faces to stop them. Chagrined by Banshee and Grundy's joyride, he takes the wheel and takes them to their set meeting spot. After the intro and title, a reporter congratulates Cyborg for finding a gem called the "Rose Stone" that will be displayed in the museum's Inca exhibit. Then a video game designer named Gogo Shoto is shown developing a game where you can be Batman. His assistant, Ana, notifies him that she's leaving for the day. She appears to come back to attack him, and Gogo tries to hide only to find the real Ana on the floor knocked out. He runs to a room where he puts up a Batman billboard to call him. The fake Ana breaks in saying that she's kidnapping him, but Batman arrives on the scene. The fake Ana shapes her arm into a hammer to knock Batman away, and then reveals herself to be Clayface and takes Gogo away.
Batman tries to follow him, but Clayface shoots mud onto a semi-trailer truck to run him over and escapes through a manhole. Silas Stone experiments with Cyborg's new parts when Commissioner James Gordon arrives and asks Cyborg to help identify the culprits behind the theft of an AI belonging to Professor Ivo. Cyborg reveals them to be Scarecrow and Silver Banshee and reports the info to Batman. Later, Solomon Grundy disguises himself as a pizza man to steal a battery at the atomic power plant. He loads is into an ice cream van driven by the Joker when Nightwing catches them, but Grundy takes him out. Batman catches up to the Joker with the same robot wolf from Batman Unlimited: Animal Instincts, but he throws Batman off the highway. At the abandoned fairgrounds on Gotham City pier, Gogo Shoto is shown hostage by the Joker who has him help pull a prank on Gotham. At the Batcave, Red Robin is playing a zombie game Gogo made while Batman is attempting to discover the monsters' motives. Alfred reminds him that the Inca exhibition is happening that night, and Batman asks for Oliver Queen and Dick to be there as well. At the party, Bruce Wayne runs into Cyborg who explains that the Rose Stone conducts energy.
Bruce sees Dick and Oliver and meets up with them. They were talking about what they were doing for Halloween and ask if he found any info on the monster villains. The ceremony starts and is interrupted by Joker who has Clayface posing as a Tyrannosaurus attack all the people. Even with the intervention of the heroes, he escapes. The heroes follow the villains around town with Batman on the robot wolf, Red Robin on the robot bat, Cyborg flying, and Nightwing and Green Arrow in the Batmobile; but the Joker unleashes a virus that makes all technology shut down. The virus also makes all technology laugh and brainwashes Cyborg into fighting for Joker. The Joker declares himself king of Gotham City, and appoints Grundy sheriff, Clayface baron of ice cream and candy, Banshee weather forecaster, and Scarecrow head of the economy—the latter issues info as the new currency where whoever notifies them of a hero gets to use technology for a short time. The heroes return to the Batcave where they try to find the crooks by reading when the Joker announces a parade on himself. They pinpoint their location to the abandoned amusement park on the pier. The crooks start arguing on why their commercials are failing when Green Arrow fires a toxic gas arrow as a distraction while the other heroes free Gogo.
Batman goes into the Love Ride where Grundy pursues him, but Batman shocks him by electrifying the water. Green Arrow sneaks around the booths after Banshee breaks his bow and fires softballs at her instead to knock her out. Nightwing enters the House of Mirrors where Scarecrow uses fear gas to torment him with his legacy, but Nightwing smashes several mirrors to reveal him. When the Scarecrow's about to slash him, Nightwing fights back and uses his own fear on him before knocking him out. Red Robin goes into the villains' studio where Clayface turns into Batman to try to trick him but finds it pointless. Red Robin finds Gogo, but Clayface finds them. He shapes into Gogo to try to fool him, but Red Robin asks a question about a video game to expose him and throws smoke balls in his mouth to knock him out. After the villains are defeated, Joker shows up with the brainwashed Cyborg, Batmobile, Batplane, and robot wolf; and he releases the villains while they're distracted. Batman handles the Batmobile by hiding in a manhole and making it leak gasoline, and he lights a fire with a Batarang to make it crash.
Green Arrow handles the robot wolf by making a model plane fall on it with his fixed bow. Nightwing handles the Batplane by damaging its power source and making it fall in the water. Red Robin handles Cyborg with assistance from the other heroes by shocking him in water making him pass out. They take Gogo to the Batcave where he gives Batman a device that allows him to enter the AI world. The Joker then decides to send the virus worldwide once the parade's over. Once the parade starts Batman gets close to Joker and enters the AI world where he sees many Jokers but gets rid of them with an upload that turns them into him.
Red Robin uses fast-hardening powdered cement on Clayface to petrify him. Commissioner Gordon tricks Grundy into using all his ammo and make him fall into a holding seat. Green Arrow boos Silver Banshee's singing and fires an arrow at her, and Nightwing whacks Scarecrow to make him pass out. Cyborg escapes from the Batcave and attacks the heroes, but returns to normal once the virus is taken out. Unfortunately, Joker plans to launch another virus and distracts the heroes with a giant mecha suit. They use vehicles from the history museum to take it out. Batman uses a plane, Red Robin and Nightwing use motorcycles, and Green Arrow uses a tank. The Joker takes off in a rocket powered suit to keep them busy. Batman deduces that Cyborg's the transmitter Joker's using to launch the virus, and Cyborg finds the Rose Stone in his left arm Gogo tells him to place it on the Joker's suits central core to shut down the virus. He places it on the Joker's back, the Joker falls into the sea, and all the technology reboots. The spooky villains are taken back to Arkham and the heroes prepare for when Joker returns. The Joker walk far away from Gotham upset that his plan failed, and he walks off into the sunrise thinking of a new plan as the film ends.
It was followed by a sequel, Batman Unlimited: Mechs vs. Mutants, which was released on July 24, 2016.