green fuzzy on Marco

[JMorris271]

I just received a load of Marco live rock. Two pieces had something green and sort of fuzzy looking coming out of some of he pores. Looks to be about 1 inch or so now. Friend or foe?
I can't get the uploader to work now so I can't get a pix

 

[whiteshark]

There is no way to make any kind of ID without pictures. It would be a complete stab in the dark.