Welcome aBoard Orionsbelt~!!

> lots of other expressions of this kind..

How about:

Hungry enough to eat the crutch out of a low flying seagull/dead dingo (or worse!!)...

Hungry enough to eat a horse and chase the jockey...

As dry (thirsty) as a dead dingo's donger...

As full as a goog... (a "goog" being an egg)

As full as a tick...

etceterah

notback yet stales