Small Red Creature...What is it??

[sulp]

I am brand new at any type of reef system and I'm having a ball learning and setting up my 12 gallon JBJ Nano Cube. It's been cycling about 4 days. When I put in the LR and LS I noticed a small, red/maroon creature poking out of the sand. It is about 1/4" long with a cylinder shaped body that blossoms out to a crown-like funnel top with small spikes. It was attached to a tiny piece of coral. I thought it looked like a creature that belonged on the LR...SO I moved him there. I am not totally positve, but I think he may have disloged from the small piece of coral and took up residence on the LR. The pic shows what it looks like when it is "open". It sometimes "closes" up and seems to shrink in size until it's almost totally up against the rock. Maybe this is a very common hitch hiker, but like I said, I'm brand new and have no idea. I've looked through some books and couldn't identify. Any help from you guys would be great! What is it? Is it safe? Will it grow? etc. I love this site and plan on spending a lot of time here! Thanks All! I'll post more pics of my new system as I go along.

[sulp]

Ooops posted twice. Please reply to above post. Thanks!

[phergus_25]

looks liek a very bad thing, aspinis

[jenniebutterfly]

aiptasia is what phergus was trying to say lol, and yes i agree

[phishen]

I'll admit, it does look like aiptasia, but don't the tentacles seem a little small? I mean most of the ones I've seen, even if they were very very small, had longer tentacles than that. If I had to guess I would say aiptasia, but unless the tentacles grow out a little bit, there's no way to tell for me.