Please help me ID this coral

[StartingInUtah]

I was given this coral to start in my tank. I was not planning on getting coral yet but have a setup that will support it so a friend gave me this piece to start with. He told me what it is and I forgot. He then went out of town and is unreachable for about a week. I want to make sure I am taking care of this correctly so I want to research it out. It seems happy in my tank as it opened within about a half hour. These are not the best pictures of it, sorry. They were taken with my cell phone but since it was given to me for free I am guessing it is a very common type of coral. As soon as I find out what kind it is I will be looking to make sure I am taking care of it correctly.

Thank you for your help.

 

[Dav3]

Some sort of button polyp or palythoa.