UFO in my tank last night... What the heck is this...

Ok, so I turn my lights off last night to go to bed... I lay down and this little UFO starts darting around my tank like hummingbird on crack... I mean this thing was hella fast... I turn my lights back on and watch it for like a minute, then it gets sucked into my overflow... I dig it out of my overflow and grabbed my camera... I took a picture of this crazy little creature and put it back in my tank... Within a minute it got sucked into my fuge...I have no idea what this little thing was... The pics are not great, as I said this thing was knarly... The only way I could even begin to describe this thing is a cross between a worm, with centipede like tiny legs... What the heck was this thing..... Thanks in advance....

 

i am thinking a spaghetti worm too.

 

Just so you know, all of the stringy things in the first pic is actually polyester threads, as when he went into my overflow I had to take a pair of tweezers and cut a section out... He was a worm like thing about a 1/4" long...

 

Could be some sort of a nudibranch?