Disclaimer: I don't own Animorphs or anything related to Animorphs which all belongs to K. A. Applegate and Scholastic.
Even though Rachel's parents were away for the weekend, Cassie was very careful while sneaking into her house. They had been planning this for weeks. Cassie the expert morph was going to show Rachel a good time. As Cassie neared Rachel's room, she started the semi-transformation. She had acquired a horse form earlier that week and had been enjoying how it felt to have a penis, particularly one so massive. Cassie would perform the morph every morning and enjoy a walk to school with the horse's soft penis moving ever so pleasurably against her right leg. Cassie let a pleasurable shudder move through her as she felt the horse's flaccid penis grow slowly down her thigh, finally stopping at her knee, just showing past her baggy shorts. Her pussy was just inches from the base of the penis, unable to experience the pleasure it would so surely give her. Even though Cassie had practiced this morph many times, she had been unable to perfect it. The morph left her with a full horse tail and fur along most of her lower body. This would give Rachel a pleasant surprise. Cassie opened the door to Rachel's room.
Cassie smiled and said "Hello hot stuff, are you ready to have some fun?"
Rachel morphed out of the cat form she had been resting in as Cassie entered the room. Fully naked, her large breasts jiggled ever so slightly as she walked towards Cassie. "What took you so long? I almost started without you."
Cassie's massive horse penis started growing erect at the sight of Rachel nude and ready. It grew as Rachael's eyes watched and her mouth began to water.
"I didn't expect a treat like this today, Cassie. I've never seen a cock so big."
Cassie removed her clothes revealing her satyr-like perfect female body with her cocoa colored skin and furry lower half. The horse's penis was against the ground and fully erect. Rachel walked over and straddled the animal cock. Cassie became uncontrollably aroused by the feeling of Rachel's warm wet pussy against the base of her cock. She had never experienced anything remotely like this before. Rachel lifted the cock up against her pussy and slowly walked backwards towards the tip, ramming the massive penis inside her the moment she reached her goal. Rachel's insides ached with the size of the animal's manhood inside her. She let out a moan of pleasure.
Cassie was astonished at the feeling she was experiencing. Her tail was twitching uncontrollably with the pleasure she was feeling. She started pumping her hips in a smooth circular motion taking her cock in the full motion of Rachel's pussy.
Rachel came with an orgasm she had never felt before. Tears of joy game to her eyes as she climaxed and a tremendous feral moan escaped her lips.
Cassie was not a virgin by any means, but this was her first time experiencing sex with a penis. She came with an intensity that she never thought was possible. Her cock exploded with pleasure which grew and grew until her pussy was climaxing at the same time. She collapsed under the power of a 4 foot cock and her pussy reaching a massive climax simultaneously. Horse cum shot out of her cock just as it left Rachael's clit drenching Rachael in warm cum and leaving big strings of splooge all over the carpet.
Both of the girls lay down gasping with pleasure. Cassie slowly morphed back into her human form, crushed by the loss of her penis. The girls fell asleep naked next to each other. Both of them knew this would be happening again.
Author's Note: This is a one-shot idea for Animorphs that wouldn't leave me alone. Please review and tell me what you think of this idea. Also everyone should check out the stories of PD31, OneHorseShay, Twilight Warrior 627, illusorygentleman, SoraOblivion62, Fanfic-Reader-88, Darth Marrs, Zane's Girl-Jo, ben10987654321, Chunk127, Kenchi618, Kathryn Claire O'Connor, Hotstreak's crossover stories, kb0, SKRowling, Kixen, Makokam, eleanorr1gby, megamatt09, CalzonaAndDemi, Quitting Time, and Amiyrasmom. I also have two forums called Harry Potter Challenges and iCarly Challenges set up for the challenges I make for those two Fandoms so if you could please stop by those and take a look to see if one of the challenges interests you enough to do.