I read it in the late 70's or early 80's. I want to say it was called "Parrot Island" but i cant say that for sure. I do know it had a colorful parrot in flight on the front over a landscape. It involved a young boy and friends or family being lured by a talking?magical? parrot into a fantasy underrealm via a train tunnel (shades of potter before potter existed) and into a fantasy war set amongst such races on various islands in a huge underground realm. I remember basilisks distinctly. I usually keep any remotely good book but perhaps it was a library book as I do not have it. My son has taken a liking to the potter series so if I could find this to give to him, it would please me. Thanks!