Poison Ivy's boss fight involves two phases. In the first, you must destroy her plant pods by throwing Batarangs. Dodge her vine attacks and spore projectiles. In the second phase, she's protected by a shield. You need to stun her with a Batarang when she's vulnerable, then use Explosive Gel on the ground near her to damage her. Repeat this, avoiding her powerful attacks and the smaller plant creatures she summons.
