It looks a lot like a teal paly that I've got taking over the softie side of my tank. It's a paly of some sort; if it's teal you can expect to see a lot more in the near future!
Yeah definitely some kind of paly or button polyp. Not exactly a bad thing to have they just spread pretty fast and can take over. I've got some brown palys that have spread like crazy.
first pic green paly looks like psamacora below it and cyno (bga)second pic scares me if the little things with the dot near the edge move and dont have a shell they are flat worms if they have a shell its strombela a form of abalone good guys