Did you know that you can get cold sores from stress? Well, you can, and I have two now. Enjoy this lava lamp in sea slug form while I collapse; I will be commuting a LOT in these next couple of weeks.
Soooo yeah, that's a Spanish Dancer (Hexabranchus sanguinus - what an awesome name!) is a carnivorous sea slug native to the Red Sea and Indo-Pacific Ocean. It is one of the largest nudibranchs around at over 40 cms long. Take out a ruler with centimeters and inches if you have to.
Besides floating around like it does above, it can move like a normal slug...but that swimming is so damn cool that nobody really cares. It was named, of course, due to its unique locomotion resembling a flamenco dancer's big, flowing skirt.