The Joker is one of the Fun Pack characters in Lego Dimensions 2: The Rise of Enoch, from the DC Comics franchise.
The Joker is unique among other major characters in the Batman franchise in that he has no official origins in the DC Universe.
According to LEGO Batman: The Videogame and LEGO.com, Joker's origin in the LEGO Batman continuity is the one most accepted by fans; Joker was once a small-time criminal, known as The Red Hood, trying to escape Batman. Red Hood fell into a vat of toxins which turned his hair green, bleached his skin white, stained his lips red, and stretched them out into an everlasting smile; it gave him the appearance of a crazed clown. Driven insane by this reflection, he renamed himself The Joker.
However, according to the January/February 2012 issue of LEGO Magazine, Joker has told his origins in so many different ways, that nobody knows for sure, possibly not even Joker himself.
Both origins agree that Joker became Gotham's most sadistic and twisted crime boss and that he is insane, but also a genius, having knowledge of chemistry, physics, and engineering; Joker invents gag-based gadgetry whilst concocting criminal schemes. The Joker also cheats death frequently, having been thought killed several times only to come back and wreak havoc once more. He has many minions serving under him, most notably his self-proclaimed lover, Harley Quinn, his psychiatrist at the Arkham Asylum who fell in love with him there. The Joker is a mass murderer and has been known to kill many people, even his own henchmen.
Joker is widely accepted to be Batman's arch-enemy, which he is noted to be in the January/February 2012 issue of LEGO Magazine.
He and Saruman were the first bad guys that Lord Vortech summoned to Foundation Prime. He asked for their request to join his plan, offering them weapons he got from multiple other dimensions. Joker told Vortech that they would be crazy to refuse that offer. When Vortech failed to understand what that meant, the annoyed Joker told him that it means they were in on that plan.
He is sent by Lord Vortech along with Lord Business to invade Springfield. When Batman, Gandalf and Wyldstyle arrive at Mr. Burns' Mansion, where he meets with the trio and resurrects his gigantic mech: the Joker-Bot, using the Chroma keystone via a unit. He attacks them with his mech, however, they are able to defeat him and his robot. As he escapes with the Keystone, Gandalf attacks him causing Joker to drop the keystone but still escape to Foundation Prime. As soon as he arrives, he is seen with an ice bag, putting it at his head, regretting losing the Chroma Keystone and thus, giving Lord Vortech a warning about Batman.
The Joker is seen with other villains when the Thief explains Vortech his failure and he responds by smashing him.
Later on, whilst Batman, Wyldstyle and Gandalf meet face to face with Vortech, The Joker attacks the heroes with his mech's gun through vortexes. Vortech later opens a portal sending the Joker along with his minions who went to Vorton, badly damaged X-PO (telling the trio that "he put a smile on his face!"), and returned with the rest of the foundation elements. When Vortech creates The Tri he and the other villains decide to escape in the event that a similar fate was in store for them.
However, if you go to the Cloud Cuckoo Land, you can see The Joker, Master Chen & Lord Vortech's army dancing.