[tang daddy]

do you find the white fluffy stuff on the digitatta?
if you do it could be a nudibranch they are small white and have frills on their back sometimes are harder to see because they can be small as 1/20 the size of a grain of rice look up monti eating nudibranch's on google images and compare it to yours, Why I say this is because you say it comes back even after you blow it off.