What is this?!?!?!

[engine_24]

I just got this slug over the weekend from the LFS, and when I got home from work I saw this! I removed him from the DT and stuck in isolation in a 3 gallon pico because if he is dying I don't want him to nuke my tank. The weird thing is that the thing coming out his back is moving!! Any idea what this is????

 

[cranberry]

Maybe flip it over and see how it moves.... it looks like it's on it's back.
And look up Bursatella leachii.

 

[tonysi]

it looks like parapodia to me-just fleshy type of growths.

 

[thefishdoctor7]

I agree with what Cranberry said, Bursatella leachii "Blue Dot Sea Hare" Definitely.