What is are these? Are they good?

[Yoan2003]

http://oi57.*******.com/1on1g2.jpg
http://oi57.*******.com/qzn1hx.jpg

I have two month old tank but these two things have been growing a bit lately and want to find out if they are good or not for my tank.

Thank you so much guys

[tkeracer619]

Sponge.

Awesome! Congrats :)

[bjwoody15]

Agree looks like a sponge.

[ginger7286]

I 3rd the sponge.

[campos]

sponge. good stuff