Can someone ID this please

[kizzy89]

During feeding this morning i turned off all pumps and wavemakers and as i was looking over everything i found this "thing" I've never seen one before which is weird. I tried Google image search but couldn't pinpoint this.

 

[kizzy89]

 

[Gray999]

maybe a nudibranch or some kind of tunicate?

 

[kizzy89]

The system is over a year and a half old and only berghia nudibranch have been in here. It slowly went off the rock on a 1/2 inch slime line thingy and got blown away by the current.