Another ID please

[jedimastermopar]

I see these all over but I can't for the life of me figure out the name? Is this a leather of some sort?

NM, giant mushroom cup coral.Amplexidiscus Fenestrafer

 

[125G Reefer]

Just looks like a Mushroom to me.

 

[sayar10]

hello,
it's amplexidiscus fenestrafer.
no?
@+

 

[gohstwrighter]

looks like my fuzzy mushrooms