I spent some time in my "vault" recently, and stumbled across an image I'd totally forgotten about. This was actually my second "Cryptoterrestrial" book cover proposal... the first being the infamous crypto face that Mac had already hung on PHB.
Mac wasn't crazy about the above image... misinterpreting it as a "crashed saucer" image. Which it wasn't really. It was my interpretation of a crypto "mirage." That is, it almost appears like a downed craft but if you look closely, it's really materializing out of the rocks as opposed to nesting in them.
Mac did come to like the image... but he was already married to that creepy crypto mug!