The American Snout is a one of a kind butterfly, the only representative of the Libytheinae family in the United States.
Because most butterfly groups are named based on physical characteristics, it's reasonable to guess that snouts get their name based on their elongated noses.
The top picture shows the American Snout with wings open. The suared forewings are a good initial field identification clue from afar.
The bottom picture shows the Snout in its usual position, wings folded, looking like a leaf and blending into the habitat. It just crawled out of its chrysalis.
They are common in the United States except for the Pacific Northwest and upper Midwest states.
You can often read stories of millions of Snouts migrating through Texas.