Flatworm?

[Gtinnel]

As I walked by tank this morning I noticed what I think may be large flatworms in my corner overflow. I've never seen these in my tank before, probably because of my wrasse, but is it something that I should be concerned about? It is basically sand colored with darker dots on it. It also has a raised ridge down the middle with other ridges branching off, it honestly looks like a dead leaf. The biggest one I can see is about 2 inches long. From googling the closest I can find is a polyclad flatworm, which will eat my snails, which isn't a big deal to me. As long as it won't eat any of my corals then I don't mind.
I can't easily get down into the overflow to remove it or poke it to see if it moves. Here is a picture, please ignore all of the spirorbid worms on the glass.

 

[stanlalee]

One of those came off the last time I dipped corals from my lfs. Not sure what it is but as one who's had small harmless flatworms (springers damsel took those out in no time) and red planaria (the multiplying devil's) whatever that is isn't something I've seen in plague numbers anywhere.

 

[BiggestE222]

I have seen a few that are similar. They just graze algae. However I can’t say they are the same. When in doubt kill it.

 

[Hincapiej4]

Flatworm.

 

[Gtinnel]

I was able to get some tongs down into my overflow in an attempt to grab one of them. When I tried grabbing one some of it just scrapped off. I am more confused about what it is now because it is not a flatworm, it is not a single animal. So it's either not an animal at all or it's a group of something, like eggs perhaps.

I've been in this hobby for many years and I'm still amazed at the diversity of things that make it into our tank without us knowing how they got there.

 

[Hincapiej4]

It's a flatworm..