My partner and I joined a live auction for coral recently. I won a favia. I bought something else. My order got messed up and I was sent 2 favia. I'm not gonna name names but the seller wont send me what I actually ordered because "the favia is worth more" despite us not wanting favia- we simply won one but ended up with two. After the discussion of this issue and being told it wouldn't be resolved, we noticed this growth on the side of the Favia. I reached out again to the vendor and was told "It's a new coral species" and "Nothing to worry about." Like I said, we were not looking for favia, we've never had one so we don't know a ton about them but we are trying to quickly learn. I don't trust the seller at this point and kinda feel like I'm being trolled because I wanted what I bought not what I won. Is this growth really another coral that isn't something to worry about or should we be worried? In the photo, its on the favia in the back. Looks like little tentacles.

Thank you for your response! I will look further into that!