http://abacusq6ixeuo7k322m7b26sny5zq4d3ot6lqe64q5agxajetncf6nid.onion/milton_1_9_1_easy_to_use_painting_program.php
There are no pixels; you can paint with (almost) infinite detail. It feels raster-based, but it works with vectors. The application is under 2 megabytes and simple to use. There are still quite a few options, including backgrounds, eraser, brush options, ...