Okay so i have a 13.5 gallon nano its the fluval evo. Everything seemed okay till checked my tank whilw the lights were off to take a good peek around and saw this snail/slug that i did NOT add to my tank! I have 3 astria snails that are accounted for. For the life of me idk how this thing got in here. This tank creeps me out with all the things it cooks up in the sand bed so im not surprised however this both creeped me out and concerned me because i know nothing about this little critter. Please can you guys help me identify what this is, how it may have gotten here and what should i do with it!?? I found it crawling on my torch when i first saw it. Should i be concerned??