Unknown and unmoving

[wvfeefkeeper80]

I noticed this on the rear of my tank last week while doing a water change. At first I thought it was a snail. This week, still there and no movement. Is this just something stuck my tank or something growing?

 

[blaxsun]

Just gently pry it off.

 

[wvfeefkeeper80]

Just gently pry it off.

I’d like to know what it is first. Is it beneficial, harmful, hideous, beautiful?

 

[Karen00]

It looks like it has a shiny/gelatin like surface. I see what looks like light reflecting off of it? Is that the case or is that just the pic? Maybe it's an egg sac?