Dingy Skipper Butterfly (Erynnis tages)
This well camouflaged, moth-like butterfly is so easy to miss, that I hadn't seen one for a few years until this spring, when they suddenly appeared to be in abundance.
Considering it's been in decline for years, its appearance was very welcome indeed.
Find out more, here:

The dingy skipper is a butterfly of the family Hesperiidae. It ranges from Europe across Asia Minor and Central Asia to the Amur region. "Erynnis tages" favours open grassy habitats up to 2,000 metres above sea level. The insect flies in two generations from May–June and July–August but in northern regions and at the high altitudes, there is only a single generation.