Holy moly big worm?

[HB AL]

So I've had this torch in my tank for around 1.5 years bought it from lfs when it was one small head and it's always really large, it is now 4 heads. I noticed one was kinda shriveled up some lately and even dying off in a spot so I decided to dip it since it couldn't hurt. About 5 minutes in I was just moving it around in the container and this thing comes off, at first I thought it was a piece of skeleton. Then when it settled it was obviously alive. I put a penny in for size reference, what is it and how bad is it?

 

[Mike N]

Looks like polyclad flatworm. Off with its.... upper body section!

 

[Havoks]

Looks like a flatworm, need to get rid of it.

 

[HB AL]

I put it on a firecracker and blew it up :mad:

 

[Mike N]