Welcome to TRT!
That is a
Toadstool Leather coral. Since you say you just got it then it is acting normal. Leathers can be very finicky about flow, touch, being moved, and they grow by molting. Right now all of its polyps are retracted and it can stay that way for a few days, depending on what it is going through. Eventually the polyps should come back out and you will see that everything is fine.
Here are a couple of pictures to help illustrate my point.
In this first shot you can see that some of the polyps are out and many are still retracted:
Now, in this second shot the leather is beginning to come out of a molt. This is the way that they grow and they will do this from time to time. You will notice that it looks kind of waxy in appearance and can even see some of the outer "skin" layer coming off. It looks horrible, but once the process is done the coral opens up bigger and brighter than before.
I hope this helps to put your mind at ease a little.
Now, with all of that being said if it starts turning mushy instead of being leathery then chances are you have a problem with it and need to figure out what is wrong.
Good luck with it and happy reefing!
