Not sure how well these pics will look - but I will take a chance and post them. My emerald crab, Mr. Pinchy sometimes gets a tad bossy with many of my smaller snails. He hasnt killed anything but he is often seen shoving them out of his way if he is on an algae eating mission. He gets "crabby" with the fish sometimes too. I decided to level the playing field a bit...I found this enormous snail at a LFS this afternoon and couldnt resist bringing it home. The shell is about 1.5" in diameter and houses a great big mottled brown / striped snail with antennas. Its actually rather pretty (the snail part). Pinchy had NO idea what to do when he came across the new snail. Even Mrgl the goby looked out of his cave to see the new arrival. Pinchy tried to crawl onto it but the snail sorta shrugged Pinchy off. Talk about payback. I am torn between naming this guy Hoover or Roomba because the moment i set him on a rock in the tank, he has systematically vaccuumed 3 fuzzy rocks totally clean and he doesnt appear to be slowing down. My lights arrive sometime this week and i will finally be able to get better photos - so sorry about those, hope these show how big this snail truly is.