Newbie - help identify coral?

[canadiandawn]

Hi all. I started a 14g sw tank a couple of weeks ago and need help identifying something that's shown up in the past couple of days. Not sure what it is, but it relocates itself, almost moves like a slug and does not like the light. When the light is off it stands up. It's a tube about 1/2 inch in diametre and about 1" tall.

I got a couple of pics of it but now that the light is on, it's shrunk. Hoping somebody can tell me what this is and if it's good or bad. Thanks!!