Brand Name LFS doesnt know

[jrock flimflam]

Not sure if we should post Store Brand names so my local big chain pet store could not identify what this is. It is in their tank and they stated it juat started growing after they got some live rock. I think it looks awesome but fear it is a STAY AWAY rather than a COOL ALIEN HATCHLING.
What do the experts think?

 

[Mono]

Alien hatchling!

 

[Sumbub]

It looks like a sponge type animal? I have one in my sump. It's not bothering anything.

 

[motortrendz]

Looks like a Petco tank with the band around the live rock. I'd think it's a sponge of some sort. But they wouldnt know that anyway lol

 

[Mastiffsrule]

Looks like a Petco tank with the band around the live rock. I'd think it's a sponge of some sort. But they wouldnt know that anyway lol

Well that mystery lasted long

 

[Mono]

I guess they collar their rocks in case they run off.

 

[jrock flimflam]

Looks like a Petco tank with the band around the live rock. I'd think it's a sponge of some sort. But they wouldnt know that anyway lol

Ding ding, which is one of my fears in getting it.
Even if this sponge is completely safe, i worry about getting bad hitchhikers.
...and I dont see the point in dipping it, as wouldnt the dip kill the sponge?