The following gallery is the result of a day's worth of searching for images of these lovely beasts. This gallery limited to moths and not butterflies, morphologically distinct from one another by, among other things, their antenna and styles of cocoon. Moths and butterflies both belong to the order Lepidoptera, but the number of species of moth exceeds butterflies by an order of magnitude.
Io Moth
Wingspan of 2.5 to 3.5 inches. Males feature very prominent eyespots.
Brahmin Moth
Looks like 70s furniture to me.
Regal Moth
Wingspan of 6 inches. Beyond being pretty, these critters are also the proud owners of the coolest possible name for their caterpillar form: Hickory Horned Devils.
Garden Tiger Moth
Wingspan of 1.8 to 2.6 inches. Their patterns serve as a warning to predators, because the moth's body fluids are poisonous.
Atlas Moth
Wingspan of 10 inches. Considered the largest moth in the world. (in terms of wing surface area) Like many moths, the adult (non caterpillar) version of the moth has no mouth, so dies within days of emergence from its transformation.
Luna Moth
Wingspan up to 4.5 inches. One of the largest moths in North America.
Giant Leopard Moth
Wingspan of 3 inches. Distributed throughout the Southern and Eastern United States from New England to Mexico.
Green Banded Urania
Wingspan up to 2.8 inches. A day flying moth found in South America.
Suraka Silk Moth
Just purty. Another of the Madagascar moths. (of which many in this article are)
Hummingbird Hawk Moth
A fantastic example of convergent evolution. Read up on it. It's fascinating.
Sunset Moth
Wingspan of 3 to 3.5 inches. Originally thought to be a butterfly, it was reclassified as a moth in 1823.
Elephant Hawk Moth
Wingspan of 2.0 to 2.8 in. It is spectacularly coloured, seeming to shimmer with green and red when in motion.
Comet Moth
Wingspan of 8 inches, and by far, my favourite moth! The adults cannot feed and live only 4 days. Two pairs of eyespots, brilliant colour, large size... this is one bad-ass moth.
SPECIAL BONUS! Here's one in action:
Source