>>149194638The phrase "green goblin" first appears in print in the 1810s. Attestation: There appears to be a couple letters to the editor of The Black Dwarf: A London Weekly Publication in 1818, vol. 2, pp 669 and 827 that is signed by "The Green Goblin."
However, apart from this mysterious missive writer, we don't see the "green goblin" phrase again until the 1870s. See for instance, Puck and Blossom by the lady Rosa Gilbert, published in 1875. On page 59, a goblin with a green complexion is described riding on the back of a wasp.
The green goblin phrase sees some ups and downs and has its first big peak in the third decade of the twentieth century. This was largely children stories but also weird references to the little green creatures related to the popularity of all things faerie in the decades before and after the turn of the twentieth century.
For all intents and purposes, green had become the default color for goblins by the Roaring Twenties.
After that, references dwindled during the Great Depression and then Green goblin references all but disappeared after the outbreak of the second world war. It is barely mentioned again until we see it on the rise starting in the late eighties and through the nineties.
Then, the title case (capitalized Green Goblin) takes off like a rocket around 2000 which I am supposing is Marvel related.