Good Witch or Bad Witch? please ID

[zoechance]

I have been watching this grow in my sump and now it is like getting big almost an inch! and I see little ones trying to form in my sump acrylic. I kinda like this 1 so hope it is not something "bad"
think its some kind of tunicate? Thanks for reading

 

[Rob&Gab]

its a pineapple sponge.

there good. they are filter feeders. its like another filter in your sump me and my girlfriend have like hundreds lol. give some away just scrape them off with a credit card and give some to people in baggies. There really good to have but they do multiply fast!

 

[zoechance]

THank You!! I will gladly cultivate them and when I have others that have grown nicely I will offer em up to my fellow reefers!!