OK, so he managed to whack the horse real good in the head. But his follow-through was ruined when the bat got suck in the wet shadow goop that made up the creature and knocked it out of his hands, which caused Casey to overbalance and fall.

So now he was more or less under it when it reared, and Casey may not know anything about horses, but he knew when something was trying to violently kill him. The thing was going to break his head if he stayed there, but he just didn't have time to move. He balled up, turning on his side and clinching his eyes closed with a cry as the thing slammed it's hooves.

...Well, OK, he was still breathing, that was something, but the breath he took was hot and his vision was white. When he opened his eyes, there was a plume of flame in front of them just for a moment. It seemed to be enough to catch the thing off balance, as it's hoof swung over his head, just inches away from breaking his nose.

He tried to get up, only to feel choked. The thing was pinning his hood to the ground and seemed to be doing it on purpose as it found it's footing. They had maybe 30 seconds to play with before it attacked again.