It mostly falls under Federal Nature Conservation Act (Bundesnaturschutzgesetz). I believe it's very localized of the penalties for killing an animal on the road.
Regardless, you'll need to call the police if you kill a domesticated animal or any larger animals. I believe rodents are too small to be reported.
The boring answer is something like a bond or CD ladder, or treasury bill focused ETF that'll give you 3% a year before taxes.
2 million dollars can safely net you 50,000 a year without working.
And since it's mostly federal bonds, you could be tax exempt up to a certain amount.
Of course this is the US POV.
And there are riskier investments that can hit 8ish% with only $600,000, but you'll be at the whim of high risk high reward.
If you're wanting to hit the tax free limit of $15,750 a year (total income) then 3% APY is $525k.
Or go super risky run options.