[Tifone]

Actually, the hyppo is the 2nd beast in Africa for number of men slaughtering... but it still reminds me too much the Disney ones XD

Well, jokes aside, on a second thought maybe - maybe - the hyppo as well as the crocodyle are a little too far from the "Raging Sea" that was in the ideas of Baalz and others.
Maybe they should be common nature/water summons?
For MA Oceania many of the other creatures people talked about seem nice... except IMHO Scylla... the Odyssey is very unclear about its nature, it's just some kind of hydra with 12 heads but not a lot more is known... not so original I think. ^_^ Maybe the Northern myths are more fitting?