For starters, there's a whole series of bottles embossed "Giftflasche" which means poison bottle in German... Some of these, at least, are also embossed with a skull and crossbones... Some seem to be pricey, others less so... I have bid on them occasionally, but never won one...
Hi Nick, There are many German poisons out there. The Giftflasche bottles that Ron mentioned are the ones that we see most often here in the US. The Kuhn Poison Workbooks are probably the best source of info on foreign-made poisons.
My personal favorite in German poisons is the green, triangular DE-DRO Giftflasche, also with a skull and bones. Those are cool bottles, and worth some good $$! ~Jim