Unknown Seaslug floating at the surface

[timz]

Hi, I was diving at Tioman Island, Malaysia over the weekend. At the end of our first dive during the safety stop, around 3pm, we realized there's something floating around.

My first thought was Jellyfish. After closer inspection, I realized it was some kind of slug which I've not seen before. I took a picture of it.

I asked the DM and he couldn't tell me what it was. And it was his first encounter with this creature.

Anyone can help me to identify this creature..?

 

[timz]

On a second thought, I'm afraid it could be some deep sea creature surfacing due to some volcanic activity... We scooped it up with a mask. and see what it is.... And it crawl out from the mask and I manage to capture a video of it.

 

[timz]

Anyone has any idea what is this??