"Jask-- no." Geralt hopped over the paddock fence in one single motion, heading toward the idiot bard who he'd let travel with him for so long for unknown reasons. "That's a selkie. This horse is not a magical creature who will shed her skin and love you forever if you hide it from her, mostly--" he leaned down to talk a look, "because this horse is a stallion." He didn't want to examine the ridiculous thing following Jaskier but his hands took him forward anyway, down the slender limbs to the fetlocks, picking up the feet. The horse shifted weight easily (against expectation) and didn't snap. Geralt sighed and rested the hoof on his knee as spoke. "Kelpies lurk in the water and take the form of horses to come on land to hunt people. They like eating skin, pulling it off their victims piece by piece."

He stood up, dropped the hoof. Came around to pull at the high withers. Ran fingers through the mane and then handled ears, looked at eyes, stuck his thumbs in the corner of the horse's mouth so it would open. Unfortunately, the horse seemed in better-than-good condition. It head-butted his chest when he let go and he pushed it back. "Jaskier, this horse has some form of albinism. It is going to cost a fortune because a fool will pay it and then it will catch sunburn on the road. Look at his legs. He was breed for some idiot lord to prance around a garden, not to outrun griffins and climb mountains."

Though to be fair that might be untrue-- a horse as compact and slender as this one might be incredibly fast, even with Jaskier's ego on his back.