Critter ID

[Ed]

I am just starting my tank back up after being out of the hobby for a year.  The rock has been in the tank for about three week and now I am getting these little white star shaped critters all over the sides of the tank.  Their centers are about the size of a . (period) with about 6 legs (tentacles).  I can clean my front glass then about 20 mins later have at least 3-6 reattached themselves again. There must be over 3 hundreds of them on the overflow and the back and sides.  Are these good or something that is going to take over my tank and if so, how do I get ride of them.  Also I have some other little things sprouting up all over, they look like the head of a Q-tip with hairs on the thinner end.  Could these be the same critters, just in a more mature stage?   Thanks, Ed