Krook is such an indispensable part of the symbolism of the book that when he spontaneously combusts another vampirine figure has to take his place; namely Vholes.

[…] but, on a sudden, as the eightieth or ninetieth bucket came suckingly up — my God! poor Tashtego — like the twin reciprocating bucket in a veritable well, dropped head-foremost down into this great Tun of Heidelburgh, and with a horrible oily gurgling went clean out of sight!

A Relative Density-based Outlier Score (RDOS) is introduced to measure the local outlierness of objects, in which the density distribution at the location of an object is estimated with a local KDE method based on extended nearest neighbors of the object.

You're going to the beach? Count me in!