Quote Originally Posted by JoeG View Post
Rich didn't invent MitD. His niece / granny / room-mate made something up tongue-in-cheek and Rich liked it so much he decided to use it.
No. The same quote from Rich definitely excludes this. Recall,

Quote Originally Posted by Rich
I will say this much: It is possible to guess.
That is, it isn't something I just made up for the story. It wouldn't be any fun for the answer to a mystery to be something I invented just for one purpose, would it? I won't finally throw back the darkness and have someone say, "Look! It was a therblewurkersaurus the entire time!" or some other made-up monster.
The monster the Giant's room-mate has invented is not possible to guess, and it wouldn't be any fun if it was the answer to the mistery.

Quote Originally Posted by halfeye View Post
Right. If it's out of cpyright, it's old, older than Mickey Mouse. Which leaves us with Lewis Caroll, myth, and the stories Cervantes railed against (which sound like fine fantasy, if in need of translation).
We've already mentioned lots of other works whose copyright have expired. Even I have mentioned one or two, though they're not really good matches.