The green man standing next to The Sleeping Bag With No Name represents the anon himself. No idea why he colored himself green, but aliens are stereotyped as "little green men."
Just before seeing the Sleeping Bag post, I had read A Shropshire Lad, A. E. Housman's 1896 book of poems. The fourth poem in the book, called "Reveille," begins, "Wake: the silver dusk returning" -- which I initially misread as "Wake: the silver disk returning," as if it were about a UFO. The poem's concluding stanza also caught my eye:
Clay lies still, but blood's a rover;Breath's a ware that will not keep.Up, lad: when the journey's overThere'll be time enough to sleep.
In my previous post, "Life Is Romantic, The Travail of Passion, and the Sorrowful Mysteries," I had mentioned the rite in Leviticus 14, where a bird is killed in a clay vessel ("clay lies still") and a live bird dipped in its blood and set free ("blood's a rover").