Maybe your fox and tanuki as balloon penises; like the kind I am (info on the way my idea works is in my profile (though it's kinda complicated I guess), there's no cum in my idea though either). Could be cute for them to be teasing each other till they get long and pop like balloons. :V

(can see an animation of the general idea here, but it's missing some details like being smelly and sticky, as well as the balloon knot on the tail: https://www.furaffinity.net/view/35621252/)

For the TF part, maybe they notice a zipper on each other and unzip it to reveal they've been penises all along, and were just wearing a disguise. :p

cat flattened and folded. leaking milk and cum as she compresses further.

you can try two friends becoming the breasts of your cat ^^

Two furries baing absorbed into female breasts :3

An idea;
A spiritual sequel to https://www.furaffinity.net/view/41079983/
Your shaft folded and plugged right up your rear, pumping your own body full of cum, so as to work as a counter-weight to your helium head-
Essentially turning ya into a bopper toy! Heavy round body, light bobbly head~!

how about Cat round up a couple (maybe 3 or 4) other characters and assimilate them including herself into one being with multi dicks and boobs and cat would be the main control of her new body

I have one idea you didn’t do this one. But any animal of a sitting position on the head. Meaning ass touching the head. You can add cum, cock, breasts or not you’re choice.

Rabbit using his head to give himself a blowjob. However, his head pops from filling up with cum.

Literally, anything with their genitals and buttholes morphing is a win for me.