Melf of the Green Arrow, aka Prince Brightflame, was a character in Gary Gygax's novel Artifact of Evil, but he was also the primary player character of Gary's son Luke after his previous character, Otis the Ranger (of Temple of Elemental Evil fame) perished within the Tomb of Horrors - a fate I'm sure many a D&D fan can well relate to!
Luke-as-Melf was Gary's primary in-house playtester in the 80s and played through what ultimately became The Lost Caverns of Tsojcanth, Forgotten Temple of Tharizdun, Dungeonland, The Land Beyond the Magic Mirror, and reportedly at least some of the dungeons depicted in Gary's novels. The adventures of Melf have always been a point of interest for me, both because those are adventures I know and also have played (unlike the earlier Greyhawk Castle stuff that has never been published and probably never will be) and because Luke's not that much older than me (about 4-5 years) and was pretty much a kid when he was playing through these adventures, just like I was. I can relate to Luke and Melf's adventures within the fully-formed AD&D paradigm more than I can to the stories from the formative years of the early 70s when they were still experimenting and trying to figure out what exactly it was they had come up with.
Luke is still around, he's the main man behind Gary Con, and a few years ago he also stopped by my friend ScottyG's forum and shared some info about Melf and his adventures.
Most intriguing to me from those posts was the info he provided about the powerful magical artifact that was in Melf's possession for a time - Zagyg's Spear (aka Zagyg's Needle). This item was apparently discovered in a haystack in the dungeons beneath Castle Greyhawk, which Melf burned down rather than searching through. It had a large number of powerful magic abilities: it could change shape from as small as a needle to as large as a pike, was a magic weapon with a bonus from +1 to +8 (presumably determined randomly per use), allowed flight at will, invisibility at will, and even planar travel at will. However, it also brought the user to the personal attention of the mad demigod Zagyg, who demanded worship and also passed judgment - and ultimately took the item back from Melf when he was found to be insufficiently chaotic (read: when Gary decided the item was too powerful).
I love stories like this. They help humanize and personalize the sometimes-distant tone of the published books. You get a picture of what Gary's games with Luke were like, and how cool it must have been as an 10 or 11 year old kid to have a D&D character with a bad-ass magic item like that! That's the kind of stuff I love in this game, what keeps me coming back to it and dreaming about it even after all these years - a kid having awesome adventures and bonding with his dad.