The nudibranch Glaucus atlanticus was a trending topic among biodiversity networks earlier this year when it was first sighted in Taiwanese waters  and referred to as a living pokemon.
Glaucus atlanticus, commonly called the blue glaucus or blue sea slug, is the only species of its genus. Unlike its relatives, it floats upside down on the water’s surface!  Not your typical nudibranch, aye?
 Lin, H., and L. Lee. 2012. Blue sea slug makes debut in
. Taiwan Times. See http://www.taipeitimes.com/News/taiwan/archives/2012/02/14/2003525453 Taipei
The SeaLifeBase Project