Greg watched the thing fall with a humph of satisfaction, though he didn't trust that it was down for good. He did have time to face the girl - familiar, probably from school, probably someone he should have known, damn it - and he approached her carefully. He'd seen people lose their shit from that blood, he was hoping she had a bit before it happened to her.
"If they're loose they'll come back this way," he said, trying to soothe her though he had no bloody clue about the habits of horses or any other animals. "They'll come back and you need to be around to care for them. Just...hang on a minute, okay? Let me finish this thing off. And don't...don't watch or anything." He studied her, but she seemed to be sliding into her own little world. Which meant the yelling and the seeing things was probably coming fast.
He gripped his club and headed over to the downed monster. Had to do this fast and get her to help before she started freaking out. Not wasting a second, he stood as far from it as he could and started bringing the club down on its head. Over and over again, hard as he could manage, until anything identifiable as a face was long gone, and the thing was still as stone. He checked himself fast for any spatters of blood, and wiped the club off carefully in the grass.
He turned his back on the thing and headed back to her just in time to see her reaching for a slime-covered bag. He dropped the club and lunged to grab her arm right as she was about to touch it. "Wait, wait! Gonna make yourself even worse."