I think that rendering down emus for their lard or tallow or butter is another thread ...
... and I just flinched and spat at the thought of "slug beer" being made FROM slugs. Yuck-o!
It's bad enough to have read the story of the gardener who put down his can of beer on the porch and went to do something ... then came back just in time to see the slug that had crawled up onto the porch, up the table-leg, up the side of the can, and was about to plunge INTO the can to meet his beery fate.
Bad, but better than coming back two minutes later.