Just noticed this. What is it?

[Spydersweb]

I just noticed this on my rock work and I have no idea what it is? Is it good, bad, natural? It’s hard to see, and it’s pretty much clear.

 

[Copingwithpods]

Possibly a branching sponge, if so not harmful. Looks very similar to some I have

 

[ScottR]

Hard to tell from pic. Perhaps sea cucumber

 

[Mike N]

Yep looks like sponge.

 

[ScottR]

Could be a sponge too. My eyes are bad. Here’s a pic of a sea cucumber buried with its feeders out.

 

[Scotty Buttons]

Looks like a acro eating spider. Got any acros?