The Sewage Banshee Grendels are one of two Toxic Grendel breeds by Grendel Man. They are like Toxic Norns in the fact they can live in a toxic enviroment. But they cannot take any cures at all, only toxins. Medicine One, in particular, can quickly kill a sewage banshee. Also, they are amphibious, and cannot lay eggs above water (This doesn't actually work-I plan on making a new version sometime soon that fixes this problem-Grendel Man).