Since autumn is coming around, the squirrel (Flint) has plenty of food he can eat, with an abundance of acorns, berries and other such delicacies, but the fox (Souji) can't really share in this fruitful harvest, being unable to work through such food. Fortunately for him, his tail is able to absorb the nutrients he needs off of his prey instead, making Flint a somewhat easy to catch battery for himself.

The way his tail works is that it absorbs energy by releasing fluids within, that soak into it's prey's fur and contact the skin. After a while, it absorbs the liquid back into itself, with any nutrients it could pull along with it. It is a slow process, and doesn't harm the prey outside of tiring it out, which helps with keeping them still. Also, similar to a LikeLike, it can only really dissolve through clothing, which while providing him with a bit more nutrients, is mostly to be able to get at the skin of it's prey. Unfortunately for him though, Flint is a bit too attached to his pants, being one of few objects he actually owns, so the fox does him the service(disservice?) of removing them while he is restrained by the coils of his tail.

Nutrients isn't the only reason he does this though, as he simply enjoys teasing his mate, keeping his head from being consumed, so he can ruffle his head-fur and watch his embarrassed squirrel as the pulsing walls of his tail press against him, and the effects of the slow process of energy being drained out of him.

This wonderful sketch was drawn by  SnackTime. Please go check out their gallery, as they draw the most wonderful and loving endo-artwork on FA.