Skyr is a food product from Iceland. It's a dairy based yogurt-like substance (though thicker) and is very high in protein while being low fat. Regular, unflavored skyr has about 13g of protein per 100 while the flavored usually has slightly above 11g of protein per 100. It's most common to buy it flavored or mix flavors after buying the unflavored version due to the bitter taste of the unflavored version. It's very healthy and completely natural.
Example of store-bought strawberry skyr:
Nutrients in 100g:
Energy 394 kJ / 93 kcal
Protein - 11.2g
Carbohydrates - 11.1g
Fat - 0.4g
B2-Vitamin : 0.22mg : 14%
Calcium : 84mg : 11%
Phosphorus : 140mg : 18%
It's very common for athletes to eat a lot of skyr due to its high protein content.
If skyr was produced in other countries it would gain immense popularity due to how healthy it is (while having lots of energy).