The Joker committed crimes with his comedic weapons which included his famous acid-spewing flower that was always tucked into his lapel. The infamous flower that the Joker wore in his lapel sprayed (at any given time) acid, poisonous laughing gas, water, knock out gas, or nothing at all. The flower's colors varied over the years, but were usually yellow or purple.
Initially this item appeared as one of Joker's many harmless pranks in the 50's. After the watergate/Vietnam era the flower starting to spray lethal acid and poisons.
Television and film
The Joker wore a flower that sprayed water, powder, and knock out gas. Never emitted lethal contents.
- "Have a little whiff of my posy."
- ―The Joker to Vicki Vale.[src]
In the 1989 film, Batman, the Joker referred to his acid flower as his 'posy' and sprayed at Vicki Vale, who managed to dodge it. The acid flower is used again toward the end of the film, to melt the seal the held the bell to the Belltower at the Old Gotham Cathedral to make the massive bell plummet through the stairwell, preventing the GCPD from pursuing. Batman narrowly avoided it while ascending the stairs.
In the Season 2 episode Harley and Ivy from Batman: The Animated Series, the Joker first used the flower in his lapel to spray laughing gas at Poison Ivy. However, Ivy simply laughed, and told him the gas would not work on her (because of her immunity to poisons), much to Joker's surprise. She retaliated by dealing Joker a savage karate kick to his crotch that was hard enough to temporarily alter the pitch of his voice.
The Joker later used the flower in his lapel to spray laughing gas on his victims in several other episodes in the series.
The New Batman Adventures
In The New Batman Adventures, the Joker used the lapel flower once to spray laughing gas, and another time was able to defeat Superman with it. The Joker, during a battle with Superman, tried to use Kryptonite on him, who had come prepared with a lead suit. However, a dismayed Joker soon remembered the flower in his lapel. Joker squirted green acid from his lapel flower all over Superman, which destroyed his lead suit and allowed for Joker to gleefully shock him with his Joy Buzzer, as Superman was exposed to the Kryptonite.
In season 5 of Gotham, the series' Joker equivalent Jeremiah Valeska often wore an orange-red lapel flower on his suit. However, this appeared to be a regular boutonnière flower that did not spray any substances. Jeremiah's lapel flower was last seen when he fell into a vat of chemicals at Ace Chemicals during the No Man's Land crisis.
The flower appeared in season two of Batwoman. It was seen in the Batcave, along with other trophies that bruce had taken off his enemies. In Kane, Kate, Kate (under the influence of the memories of Circe Sionis) stole all of the artifacts (including the flower) on behalf of Roman Sionis and Safiyah. In Power, Alice uses the flower against Roman and proceeds to say that the Joker is the greatest villain.
The Joker is a playable chatter able to use the squirting flower.