Batman & Robin 3: The Joker's Last Laugh is the sequel to Batman & Robin 2: Power-Crazed Penguin, & the third film in Nick Weintraub's Batman franchise.
The film begins with Jason Todd coming back to life, & out of his Grave while wearing a deformed version of the Robin suit, attempting to walk back towards Wayne Manor. He is shivering on the way
Joker plans to spread laughing gas over Gotham City from the Cathedral, but also wants to cause mayhem for Batman.
He sends Mad Hatter to Ace Chemicals to retrieve toxins while he and Harley Quinn set a trap for Commissioner Gordon. Hatter was defeated by Batman and Robin, and Gordon captured by Harley and Joker.
Joker sent Batman a transmission of what they were planning to do to Gordon if Batman didn't arrive to rescue him. Reaching the Amusement Mile, Batman and Robin made their way to rescue Gordon where they also defeated Harley Quinn. Joker, however, escaped in his helicopter.
While the Dynamic Duo tried to chase his helicopter down, The Scarecrow arrived in his Bi-plane to try and send them "...tumbling to the ground." However, the bi-plane was shot down and crashed into Joker's helicopter. Both villains were left for dead, but they escaped with giant balloons and crashed through the Art Gallery's skylight. They tried to escape, but Scarecrow was grabbed by a Police Officer in a crane. Joker escaped by using his laughing gas on a police man.
Killer Moth met Joker outside, and together they made their way to the Cathedral. However, an enraged Gordon ordered three mobile police headquarters to stop them. They defeated them all in the clown walker, and rescued Harley Quinn. Gordon called for Batman's help, and he quickly arrived in the Batwing. With the searchlight on, Moth was attracted to the light and stayed while Joker and Harley made their way to the cathedral. Moth realized the danger he was in and fled, but Batman and Robin chased him through the streets until he was cornered and left unconscious. When he came around, Robin threatened him with bug-repellent and he told them Joker's plans.
At the Cathedral, the Dynamic Duo chased Harley to the top of the tower where she and Joker and hid in giant bells. Once they were found, Joker summoned his helicopter to defeat Batman and Robin, but it was destroyed. The platform Harley and Joker were on collapsed, and Harley was knocked unconscious. During the fight with Joker, the Clown Price of Crime managed to win and used his joy buzzer to defeat the Dynamic Duo. By the time Batman came around, Harley was already revived. He threw a batarang at the bells to disrupt the bats' echolocation and they attacked the villains. Harley & Joker were scared, desperate for escape, so they tried running out one door, but Batgirl was inside, so they chose another door, but it had Nightwing in it. They kept looking for an escape door, running into Batwing, Spoiler, Azrael, Huntress, Red Hood (to which Joker said after running from him, "He somehow seems familiar", referencing his past life as Jack Napier, then known as the red hood.), Batwoman, Hawkfire, Beyond Batman & Blackbat. Soon after that, Joker & Harley left the Cathedral, and Gordon arrived shortly thereafter to arrest them.
They were placed in their cells next to Mad Hatter, Scarecrow, and Killer Moth.
Batman and Robin scale the side of Arkham, and Joker looks up at them and shakes his fist in anger while shouting, "screw you, Bat-lame & Slobbin! If it weren't for Bat-bitch & those other foolish meddlers, I would have gotten my way but you all crashed it!" Then Scarecrow can be hear grumbling "Get over it, stupid clown!" Then Joker's heard shouting, "Me, stupid?!? You're the one with straw instead of brains!". At the top, the Dynamic Duo see the Bat-signal shine, aim their grapple guns, and move towards it.
- Kevin Porter as Bruce Wayne/Batman
- Nicholas Weintraub as Tim Drake/Robin
- Sean Connery as Alfred Penniworth
- Matthew Hiscox as Dick Grayson/Nightwing
- Christopher L. Robinson as Jason Todd/The Red Hood
- Kristen Stewart as Barbara Gordon/Batgirl
- Lyle Weintraub as James Gordon
- Jennifer Zhang as Cassandra Cain/Blackbat
- Charissa Saverio as Helena Bertelli/Huntress
- Chloe Dykstra as Stephanie Brown/Spoiler
- Joey Rassool as The Scarecrow
- Uncast Actor as Killer Moth
- Timothy Spall as The Mad Hatter
- Rayne Bidder as Harley Quinn
- Anthony Misiano as The Joker
- Beau Marie as the voice of The Joker
- Chris del Castillo as Joker Goon 1
- Michael Ly as Joker Goon 2/ S.W.A.T. Member 4
- Ryan Pietz as Joker Goon 3/ S.W.A.T. Member 5
- Narvin Seegoolam as Joker Goon 4/ S.W.A.T. Member 1
- John Spartan Nguyen as Joker Goon 5/ S.W.A.T. Member 2
- Adam Thomas as S.W.A.T. Member 3
- Michael Pao as S.W.A.T. Member 6
- Wil Magno Alejandrino as S.W.A.T. Member 7