Clear Swirly Thing On Rock

What is this thing? Kinda has the look of a sponge. Good or Bad?

 

Might be a sponge, no idea on good or bad. But those monster aiptasia on the other hand....

 

Yea, I know. I have one really big one but you only need one.

I need to drag the rock over to the main tank so my predators there can get them but was afraid to with whatever that is on the rock. Thought I would identify it first.

Probably be ok to move the other one tho.

 

Hopefully someone will recognize the hitchhiker.

 

Thank you, I hope so. Not sure what it is but I'm getting some really cool hitchikers from my coral guy. Hate to kill it and find out it is a good one.

 

Anyone...

 

It does look like a sponge to me as well... more like the beginning of one.

 

Do you think the coloring will change. I kinda like the swirly confused look.

If you look closely at the second picture, on the right hand side, it looks like there is a half circle. ...

 

I think so. They usually change to their definitive color as they grow and get more water flow through them. I've seen them in my tank in white, yellow, gray, orange.

 

Thanks....too cool.