It's tastes a little of beer (the yeasty flavour) but there's a salty taste
too, and something like vegetable stock flavour as well.
Yabbies breed in 'dams' I guess that equates to small agricultural ponds or
something
there's a yabbie 'farm' at heathcote, vic
maybe they have a web site now, I know they'd asked me about making them one
quite a few years back when I lived there. there's also a larger variant of
the yabbie from west aussie, I dont know a lot about them except they grow
bigger and are more viable as a food product for that reason.
back on the vegemite.. you might have something like promite (english stuff)
that tastes vaguely similar, but awful.