Green hurtles their way and Frisk's thoughts go from 'considering where to dodge' straight to 'TEETH TEETH TEETH--'

They fling themselves to the left and backwards, feet tangling in reeds, screaming in tandem with the Batman's shriek when they slam down into the mud, elbow catching a rock. They don't think to get to their feet or even flip over to crawl, they're just scrambling away with the back of their pants dragging through the mud further.