Does it look like a mini kenya tree (or a branch from the kenya tree)? Does it retract into the rock when you touch it? Google aiptasia, does it look like that? Kenya tree and aiptasia look very different.
they do retract when bothered but not into the rock more like a tube, and come back out a few min later, the heads dont look like aptaisa, but knock on wood ive never had an aptaisia but they are so small its hard to tell