The original Injustice Gang of the World that does battle with The Justice League on many occasions includes Poison Ivy.
Poison Ivy joins the Secret Society of Super Villains to help them get the better of The Justice League.
She later joins an incarnation of the Society formed by Lex Luther.
At one time, Poison Ivy is also coaxed to become part of The Suicide Squad during which she captures Count Vertigo using her special abilities.
She becomes friends with Harley Quinn, The Joker’s sidekick. However, unlike other villainous team ups, this partnership seems to be real as Poison Ivy tries her best to save Quinn from any of the abuse that The Joker might inflict. She also sympathizes with him as he gets mistreated by the man who she falls in love with. Poison Ivy dislikes The Joker mainly due the mannerism in which he treats Harley as this reminds her of the way in which she was treated by Jason Woodrue.
Although, Poison Ivy has numerous motivations that are quite different from those of the other villains of Batman, Poison Ivy does not seem to mind forming an alliance with any other villain if it helps her achieve her goals.