Hitchhiking corals? ID please.

[SuncrestReef]

I have noticed two of these little corals on rocks at opposite ends of my tank. They don't look like any of the corals I actually placed in my tank, and I started with dry rock, so I have no idea where they came from. Is it common for a coral to be a hitchhiker?

Each is about 1/4" diameter. Any idea what they are? Here are some detailed macro photos:

 

[SuncrestReef]

Nevermind, I think I figured it out. I used to have a pocillopora that died a couple months ago, but during that time it looked like some polyp bailout was taking place. I think it managed to spread to a couple new locations before I removed it. Here's a side by side comparison:

 

[lilfish717]

Definitely that.

 

[lilfish717]

That is a beautiful coral as a baby like that though!

 

[Hemmdog]

Amazing