Jess saw the octopus costume and was curious at what it was. She only saw the tentacles however and didn't see a head anywhere. The odd thing about the costume was it came with a bra but not a normal kind of bra. The bra was ginormous and was meant for someone with bigger than her, it was probably for people with G or H cup breasts. The design was not your typical design either, the bra was only a band of seaweed with a knot to tie it together at the back. If someone with big enough breasts wore it, they would have a lot of underboob and cleavage.
When she was putting on the costume, she put the bra on first. She slid it on around her and tried to cover her nipples as best she could. She ended up holding it up the entire time. When she put the tentacles on, she saw two of the plastic tentacles were hollow and assumed that they were where you put your legs. She slid her entire legs in but a lot of space was left over in the tentacles.
After getting the costume on, she stood up and looked in the mirror. She looked quite good in the costume but she did have to hold the seaweed bra up.
In the next moment, she felt weak and fell over. She felt a strange pressure in her chest and a even stranger feeling in her legs. As she looked at her chest, she saw her breasts were getting bigger.
They were going from B cup to C and they eventually ended up at I cup. She could feel that they filled the seaweed bra but they were actually too big for it and were pushing against the seaweed. Seaweed is actually quite strong so it was keeping itself together nicely but squeezing the breasts together.
Her legs on the other hand felt different. She couldn't feel them any more but tried to move them. She could move the tentacles strangely and she could also bend the tentacles in ways that her legs couldn't do. Even the tentacles that her legs didn't occupy could be moved which freaked her out. On each tentacle, she could feel the suction cups stick to the ground and at the center of the 8 tentacles was her altered vagina. It looked human but it was in a spot where a human wouldn't have it. She could also feel that her anus fused with her vagina.
Jess was now a half octopus and half human creature. She was a cecaelia now.