It's true traditional Bavarian cuisine has not traditionally been the most vegetarian-friendly, but times change, and now that Oktoberfest shares the month with Vegetarian Awareness, we might as well incorporate some German-inspired vegetarian dishes so the animal loving/health conscious among us don't have to miss out.
Sauerkraut is one of the signature dishes for a traditional Oktoberfest feast, and it's already vegetarian all by itself. Not only is it delicious and nutritious -- thanks to its vitamin C content, sauerkraut prevented most of Europe from developing scurvy through long, dark winters -- but kraut is ridiculously easy to make at home. Just shred a head of unwashed organic cabbage and put it in a glass jar with plenty of sea salt. As the salt draws water from the cabbage, press the shreds down with your fist to keep it submerged. Throw a towel over it to keep the dust out, and two weeks later the brine and the bacteria combine to ferment the cabbage into kraut. You can liven things up a bit by using red cabbage or throwing in other sliced-up veggies. You can even add shredded apples to sweeten it.
Traditionally, schnitzel is a cutlet of some kind of meat -- often chicken but also veal or pork -- pounded with a hammer until it's thin, breaded, and fried. Doesn't seem to be much opportunity here for vegetizing it, but that's why you've got to think outside the box. It can be done with meat analogues like seitan or tofu. But even better is when vegetables, like eggplant and portobello mushroom, can be substituted.