Is this a hitchhiker or something else?

[laezur]

So after removing a vermatid snail from my leather recently, it's started to recover after being moody for the night. I did notice this weird lump like growth though that I can't tell if it's coming from the frag plug, or the leather itself - anyone know what it is?

In person it looks kind of like a pebble, but it seems attached to the leather and is purple. There's so much debris and crap on the plug from when the LFS sold me it, and I don't know what's good and what isn't, or what I can remove safely.

 

[KrisReef]

Leathers grow/attach to plugs, rocks, shells, or generally the substrate or rock, coral, whatever they bump up against. It looks kinda like a shell, who knows if there is something alive inside, but it will not be moving if the leather has "rooted" around it. IF you pull whatever it is off, it may leave a tear in the leather. If you leave it there, the leather will grow over it. IF you lightly pull and can remove it then it will no longer be a concern.

 

[laezur]

Leathers grow/attach to plugs, rocks, shells, or generally the substrate or rock, coral, whatever they bump up against. It looks kinda like a shell, who knows if there is something alive inside, but it will not be moving if the leather has "rooted" around it. IF you pull whatever it is off, it may leave a tear in the leather. If you leave it there, the leather will grow over it. IF you lightly pull and can remove it then it will no longer be a concern.

Okay cool, I'll probably just leave it there then. Just thought I'd check while I've recently been working on it, would rather deal with all problems now than let it readjust and then start working on it again