Hi Alan and Friendly
To Reef Central
Glad you found the lighting thread informative Alan. Lights need not break your budget and with a little reading you can find corals that can be used to stock a fairly low intensity tank. Also, simple things like placing a light hungry coral high on the rock work, can allow success with these critters too.
Friendly,
That is called a hitchhiker and they are quite common when adding new LR to a tank. You'll probably find other hidden treasures as your tank matures.