This will keep you guessing!!!

Hey guys...so in my 10 gallon quarantine I have this weird looking thing in my tank! I have a HOB filter on it...and sometimes on the little intake tube with slits at the bottom that goes into the filter itself is this weird creature on it! I have no idea what it is...its about half an inch long...its whitish/clear...it looks almost like some weird lifeform. It had legs and eyes on it...and it knows when I'm around! It looks like it almost crawls thru the water...not so much swims, but definitely is smart enough to hide for cover! I honestly only see it on SOME days, and it knows when I'm looking at it and runs. I swear to god I'm not making this up I have no idea what it is. I googled ghost shrimp and from what I can tell its not that...its just this weird looking thing...its like a mix between a shrimp and a fish...only because to me it seems so aware of my presence. Once it goes off the intake tube it hides behind a rock and I cant see it. There is NO way I could catch this thing. I honestly am stumped...I'm sort of afraid of it...but sort of not...I'm just not sure if its harmful or not. I'v noticed it for about 2 months now...but fear its been in there much longer...and wonder if theres more that I just dont know about...