This is a book that was published by www.mirrorstonebooks.com around 2007/2008.
It is really interesting and fun.
Recently I found some scans of a few pages:
http://www.flickr.com/photos/115_is_awsome/sets/72157634584421362/with/9257529306/

1261334 Whatever helps others in making a good monster. I'm good with this.

I'm pretty good at making monsters. I mean I like Greek and Roman mythology and I love drawing so I like to call it a perfect combination for creating new and freaky monsters. :P

Does anyone here know what a Incorporeal living...erm...'breathing' being would classify under?
I don't think they fit under spirit as they aren't dead, but they are incorporeal entities sooo...

I need to know where to put my creations after all.

3209679 Geez. I'm really sorry that I didn't answer you until now, but this group is rather USELESS at the moment which is why I don't pay much attention to it.

I would put it under "spirits", unless your creation is, like, stuck in a dimensional instability and is thus intangible.