Well, after some additional research I believe it might be related to a Sea Hare I introduced to the tank to rid it of Hair Algae, by the way they do a great job. I was told that it most likely a some type of nesting used for eggs.. However, since there is no mate for the little ugly guy... there will be no little Sea Hares.
It has been a few days and the ball of silly string has lost a lot of its color.. it is not the florescent green as when it first arrived.