Grosse Arnspitze (2196m) is the highest peak in the Arnspitze group (wikipedia link).
There is a hut near the peak, however, this hut is unattended, and getting food/drink is not possible there. However, if one carries food, it is possible to cook there. Also, it is possible for a group of 2-3 people to spend the night at the hut.
The ascent is from the north and passes through Riedbergscharte. The descent is through the route 851 and leads to Scharnitz, Austria.
Since the hike starts in Germany, and ends in Austria, one should carry passport, as there might be random immigration checks at border.