This is the Cretan Stitch on wool stitched in an irregular manner. It is one I use a lot, because it flows so well.
Here is a sample using it as a filling stitch in an assortment of threads by stitching it close together. The second one down is the fuzzy thread I've been using but the eyelashes are matted down by the close stitch. The left side is a rayon over a ribbon thread.