Help!! What is this?

[Weidaliang]

There’s something in my hammer coral.. should I be concerned.

 

[EeyoreIsMySpiritAnimal]

Does it "wave" at you? If so, it's a barnacle! Harmless, cool to watch, and unfortunately usually don't survive long in our tanks.

 

[Weidaliang]

Does it "wave" at you? If so, it's a barnacle! Harmless, cool to watch, and unfortunately usually don't survive long in our tanks.

It does seem like it’s trying to grab something.

 

[tbrown]

+1 looks like a barnacle.