What was the name that Bastain yelled out the window to save fantasia?

According to the website of Neverending Story, the name was Moonchild.. however, the book differs in reasoning or simply we just assume that the name he called out Moonchild is his mom's name.

He says "moonchild" I never could understand him either, but I just looked it up on the imdb in the "memorable quotes" section.

In the book, he names the Empress "Moonchild." I feel they left it unintelligible in the movie just to be sort of true to the book???

But it was s'posed to be Bastian's mother's name in the movie, yes.

Moon Child

is what i got of a trivia web site listed below

I could never understand it, it always sounded like something different. I thought they were leaving up to your imagination at one point.

it was his mothers name, but danged if i can remember it. check imdb.com. they might have it in the quotes section.

moonchild

Selene (Is his mother's name)