Pamela Lillian Isley was on vacation. She had just been released from Arkham Asylum early due to "good behavior".
Ha! As if. She knew how to turn the simple houseplants they allowed her into more of her hormone-stimulating mind control dust, so she used it to subtly convince Jeremiah Arkham to let her go without any press. The poisonous effect needed more specific and exotic extracts to be mixed in, but leaving Arkham alive meant that even Batman had to believe her legitimacy for the time being.
Still, it felt good to relax in Central Park among the plants. Pam's skin was made up to be Caucasian instead of green for the time being, as she didn't want to be instantly recognized. She exited Central Park and headed towards the Museum of the City of New York, where there was a sign highlighting two major exhibits. One was of an exotic plant species that had the capability to withstand extreme temperatures and pressures, and the other was a legendary gem that increased the size of the owner, at least that's what people believed. Pam knew she couldn't resist getting her hands on the plant, and the gem would make a great added bonus should there be enough time. Pamela decided that her vacation time was over. Now, it's time for fun as Poison Ivy.
Leaping acrobatically into the branches of a Central Park tree, Pam used her overall control of plantlife to form her signature one-piece costume out of the leaves, which shredded her normal clothing and completely undid her fleshtone makeup. She hadn't seen herself in this costume for many months, and giggled to herself at how it snugged tightly to her amazing curves and showed off quite a bit of her cleavage. The last time she had her measurements checked in prison, she was an E-cup, but with all those nutrients in the leaves she wouldn't be surprised if her breasts had grown slightly larger. No matter, though, because Poison Ivy was going to create the invincible plants she needed to achieve her ultimate goals.
Breaking into the museum exhibit was easy. Using her figure, more of the dust, and some trees from Central Park, she either forced her way down or had people kindly step out of her way. As it turned out, the two exhibits were side-by-side, and the guards were too entranced to shoot her in the process. She found the potted plant, and gave it a touch. The feeling she got from sensing its power was almost erotic, as her other hand nearly reached for her breast. Mentally smacking herself in the face, Ivy focused back on the task at hand. Putting the plant in a newly-grown wooden holster, she had one of the branches carry it out and move it back towards Central Park, where she would make a hide-out of sorts. (Not so hidden, but well-protected.) She had another branch grab the gem for her, since it was right there, and rode one last branch back out.
With the police baffled and her new Central Park lair built by the lake, she flipped a leaf from one cup of her outfit (which instantly grew back) to see which prize she wanted to try out first. To her surprise, it was the gem. Standing a short distance from the plant to protect it, she picked up the gem and waited for something to happen.
The effects almost instantly started. With a tingling sensation in her breasts, butt, and muscles, Ivy found herself growing. In fact, she was growing faster than her suit of leaves could catch up with her. She summoned more leaves from Central Park, but it still wasn't enough. Her breasts and butt were also getting larger by proportion, which felt good but wasn't the first thing on her mind.
Eventually, Ivy had summoned all the leaves in all the trees of Central Park to cover her body enough to be decent. By that time, she had stopped growing and was standing at a whopping 500 feet tall. Her breasts were larger by proportion, now an honest I-cup, and her outfit revealed more of her cleavage than ever. Her butt had become a moderate bubble butt for her size, and her overall muscle structure was much firmer than before.
Ivy, still in shock from all this, noticed that the gem had disappeared, and the new plant he had just gotten was crushed. Clenching her fist in frustration, she unwittingly regrew all the leaves in Central Park back to normal and then some all at once. This intrigued her, and she felt around her body. her biceps were strong for her figure, but retained their dainty look. Her breasts were soft and perky, and weren't drooping one bit. Her butt was firm, and provided her no trouble keeping her balance.
With all the power and curves she had just obtained, Ivy knew she had to put them to good use somehow. The question was, what should she do?