Well, since I started this thread, I might as well add to it a bit now.
While the map shows basically all the places to find the Death Omens, Juggy, and Behemoths, (BTW, nice work on the map to whoever made it, and thanks to Ed for posting it
) I just want to add afew more spots.
East of the area half way between KH and PDF (basically East of the title on the map "The Hinterseas") in Uncharted Waters, I tend to find Death Omens, and on 2 rare occassions, I found Juggys.
And..........
Almost exactly West of Cuba, I have found a few Behemoths and Death Omens.