The Vogons are a fictional alien race in The Hitchhiker's Guide to the Galaxy series by Douglas Adams:

Here's what to do if you want to get a lift from a Vogon: Forget it. They are one of the most unpleasant races in the galaxy. Not actually evil, but bad tempered, bureaucratic, officious and callous. They wouldn't even lift a finger to save their own grandmothers from the Ravenous Bugblatter Beast of Traal without orders signed in triplicate, sent in, sent back, queried, lost, found, subjected to public enquiry, lost again, and finally buried in soft peat for three months and recycled as firelighters. The best way to get a drink out of a Vogon is stick your finger down his throat, and the best way to irritate him is to feed his grandmother to the ravenous Bugblatter Beast of Traal.

Later on in the book series, we learn that, far back in prehistory, when the first primeval Vogons crawled out of the sea, the forces of evolution were so digusted with them that they never allowed them to evolve again. Somehow, though, the Vogons survived, wrecked the planet, and emigrated en masse to the Brantisvogon star cluster, where they form most of the Galactic bureaucracy, most notably in the famous Vogon Constructor Fleets (which allows them a socially-acceptable way to spend their time demolishing things). The only captain of the Constructor fleet we meet is Prostetnic Vogon Jeltz.

And, yes, they are green.

Vogons are known to make the third worst poetry in the universe (see Vogon poetry).