Maybe it's because of agoraphobia or if he lonely by nature, but he generally likes going inside of the coffin he carries around and spending time by himself.
He envies even himself from a second ago, and deals with everything as fast and precisely as he can.
He is a beloved king, and there is a saying that you shouldn't challenge Leviathan unless you are determined to kill every last population of Hades.
If you strangle him weakly just to be nice, Levi will be angry.