By now, dusk was falling on the city as the streetlamps began to turn on. Seeing no reason to linger in the run-down mansion, Fionna headed toward the park. Having gained spider eyes from her most recent meal, she noticed that she could see almost as well as if it were daytime despite the darkening sky above. By pushing herself with her spider legs while slithering on her snake tail, the chimera found she could move at a startlingly fast pace. As she stopped to examine her surroundings, her left head noticed some movement in the corner of her eye, behind a small shrub. On instinct, Fionna fired a ball of web at the spot, and heard a soft yelp. Rushing toward the spot, she became confused when she saw nothing but a heap of slime and web.
"Stop." A voice commanded from behind her.
Turning to look, Fionna saw what appeared to be a voluptuous slime girl with a transparent body that continually shifted between various shades of green, blue, red and pink. The slime girl continued to speak:
"I've been watching you for a while, and saw what you did to that succubus and that arachne. Would I be correct in assuming that you desire to assimilate me in the same manner?"
Fionna's shock turned to smugness as she replied, "perhaps. Do you think you have a choice in the matter?"
The slime straightened her posture, then emitted a squelching sound as her body divided in two before reforming into a pair of exact copies of herself. She began speaking from both bodies at once:
""Maybe not, but you and I are alike in many ways. We both predate others to become stronger, though perhaps in slightly different ways. I consume and multiply to mimic other forms perfectly, while you integrate your prey into your form freely. I have reason to believe we can help each other in a mutually beneficial relationship.""
Intrigued, Fionna decided to throw the slime girl a bone. "What are you proposing?" She asked.
""I currently have the ability to split my body into many copies based on how much I have consumed, so even if you were to eat one of me, I'd have another self right there to return the favor. However, my shapeshifting is limited to copying other girls exactly, or merging two copies to multiply or enhance certain features. From my viewpoint, I could benefit from the ability to integrate creatures in your chimeric fashion, while you could benefit from being able to multiply and enhance yourself.""
"Go on," Fionna stated.
""There's a way we can both get what we want without either of us perishing. You can consume one of my copies to gain my slime queen abilities... then you can create a copy of yourself that I can consume to get your abilities in return. What do you say?""
Fionna thought about it. What the slime girl said was true, she was faced with a being with similar abilities who could easily outnumber her and put an end to her grand revenge plan. She could try to force the matter in her favor, but it seemed like a great risk.
"You make a convincing argument. I can't say I trust you, but I don't see a better option at the moment, so let's do it."
""I'm glad you came around,"" the slime girls stated. ""Now, you go first."" Saying this, she had one of her bodies step forward towards Fionna, then closed her eyes and lowered her head. Cautiously, the scientist moved forward, then grabbed the slime girl to lift her up towards one of her mouths. Opening wide, she began to slurp up the goopy girl, and before long she was inside Fionna's belly.
"Mmm, never experience the other end of being assimilated before," the remaining slime body said. "Actually feels kinda nice. Now, form a mental image of splitting in two, then try to pull yourself apart."
Listening to the directions, the chimera scientist first turned her body into translucent slime, then divided herself as instructed. After adjusting to being in two bodies at once, she regained her natural skin tones and textures before having one of her bodies slither up to the slime girl.
"Alright, my turn." The slime said. She then expanded to a much larger volume of liquid before completely engulfing one of the Fionnas. The scientist could feel an oddly pleasurable tingling from her slime-covered body as it rapidly dissolved in the fluid. Once she was completely absorbed, the slime girl returned back to a nornal size, then split herself in two again.
""Okay, time to test this,"" she said as she had one body turn into Fionna and the other turn into a harpy. She then had her chimera body consume the harpy with her pussy, and waited for herself to digest. She then grew a new pair of arms with wings on them.
"Yes, it worked!" The slime exclaimed with a voice perfectly matching Fionna's. She then turned to Fionna, saying, "thank you, I promise you won't regret this decision. By the way, I never introduced myself. I'm Elise. Might I have the pleasure of knowing your name?"
"Fionna."
"Mmm, Fionna... Has a good ring to it. If you ever want to meet up with me sometime, I'm sure we could have some fun together. There are many secrets to that slime body I could probably teach you. I'm sure you won't have much trouble finding one of my split bodies later if you're interested. Anyways, I'm off!"
With that, she quickly flew away before Fionna could even respond. Pondering whether it was alright to let that slime go, she continued to plan her next move.