Yes, Green slimer is and SPS, its a Acropora species to be more specific and a staghorn. If it hasn't bleached out or started to dieoff already, I can hold it in my frag tank until your tank is ready. If its too late or you don't want it in your tank anyway I wouldn't worry about it much, they're pretty common.
Yellow polyps, green star polyps, and most button polyps, even a few zoanthids can handle a cycle pretty well.