The "What is it?" game

[deetu]

Does anybody have any idea what this is?

It's about the size of a quarter, growing on a small piece of rock and looks like thin leather with a lip. A hermit crawled across it and nothing changed with it.
I hadn't added anything new to my tank in a while but recently started feeding my pink coraline and red macro with Purple Tech.
Is it good? bad? It's a 20 gallon FOWLR and macro tank.
Thanks for any help

 

[Sponge]

Perhaps a gorgeous sponge?

 

[David@wegetkraken]

Looks like a Leather

 

[Sponge]

What leathers are Red. I may want one

 

[David@wegetkraken]

Close-up of one of mine...similar to what I think we're seeing here

 

[David@wegetkraken]

Jawbreaker Mushroom

 

[Trio91]

Looks like a plating sponge. Touch it and see if it feels hard jello

 

[deetu]

Looks like a plating sponge. Touch it and see if it feels hard jello

Okay, so I touched it today and it feels hard but not hard lol I think I was feeling the rock under it.
I looked up plating sponge and it will be cool if that is what it is

 

[David@wegetkraken]

Should be a cool inhabitant regardless...let us know what you have once it grows out a little.