Titans, Vol. 1 #34A

Joker: Last Laugh - A Child's Laughter
The Joker has intoxicated all Slab inmates with his "Last Laugh" serum. It gives victims his frightful physiognomy and basic outlook. While the Titans busy themselves with the intoxicated Hangmen, a similarly impaired Cheshire invades the Titans' island. She overpowers the D.E.O. orphans, then Jesse Quick and Troia, and then she infects her own daughter with the serum, turning Lian into a miniature Joker! It looks like Cheshire is going to escape with Lian, but Roy arrives and shoots her with the antidote dart. Lian declares that she "hates" her father, and, tears dripping, he must shoot her as well. Did the serum create that emotion, or simply unmask one already present? Will Lian grow up resenting him for keeping her from her mother? Roy can only wonder...
Release Date: 2001