Joker Goons are henchmen of The Joker. He usually has quite a lot of them present to assist him. They often appear in lego sets involving The Joker, and are usually fought in the video games as well. In Lego Batman: The Videogame, they appeared in the levels of the third chapter of the hero levels where Harley Quinn and The Joker were fought. In Lego Batman 2 DC Super Heroes, they appeared at the beginning of the Gotham Theatre level, throughout the Joker Getaway level, and alongside Lex Luthor's Goons in Ace Chemicals and all levels beyond.
The Joker Goons' appearance have varied throughout the series. In the sets, they wear basic purple shirts and sunglasses. In Lego Batman: The Videogame, they wear facepaint in the cutscene they appear in, but otherwise resume their purple shirt appearance from the sets. In Lego Batman 2 DC Super Heroes, they come in 2 varieties: the Joker Goon and Heavy Joker Goon. Standard Joker Goons now wear yellow shirts and clown facepaint, while Heavy Joker Goons wear black bonets, white and black striped shirts, black leather jackets and mime facepaint.
In Lego Batman: The Videogame, they use the method of fist fighting as enemies, and present guns every once in a while. As enemies in Lego Batman 2 Dc Super Heroes they do the same, but Heavy Joker Goons always fist fight. When used in Free Play, the regular goons can use basic guns in both games, and Heavy Joker Goons can as well.