This is one of the few species of butterflies that flies around when it rains, the ringlet* (Aphantopus hyperantus). It appears to be rather possessive of the water it found (and yes, they drink water from time to time):
Olympus XZ-1, 112mm, ISO400, f4, 1/200s
Here's what it looks like from above with its wings open, sitting in the rain:
Olympus XZ-1, 112mm, ISO400, f5.6, 1/60s
Thanks for watching!
\* This is actually also an inside joke. I would tell you, but it would no longer be an inside joke.