I’m actually surprised (and happy!) that this question ended up being so difficult for everybody. 
I was pretty sure that after the third letter someone would guess the answer.
Getting back to the game, two N’s coming your way!
_ O O _
O F
N O R _ A _
N A _
Letters used: T, I, F, O, L, A, E, R, N
I sort of know what it is but can’t quite remember it. B?
One B
B O O _
O F
N O R _ A _
N A _
Letters used: T, I, F, O, L, A, E, R, N, B
I’m going to guess “Book of Norvag”, though the book’s full name is Norvog Noszh, with all Os.
That is correct Zax. I read a couple of places (including both the ThunderCats wikis) and there it is spelled as “Book of Norvag Naj”, so that is the one that I went with. Anyways, your turn!
I was thinking it was something like that, but I didn’t have a clue how it was spelled, and indeed I can’t even remember what that book is!
Uh-oh! Time to update those wikis. [emoji4]
Okay, new puzzle:
Lets try for an E!
Three of 'em!
_ E _ _ _ _
_ _ _ E _ _ _ _ _ E _
Any R’s?
I tried to update one the other day and had all of my changes reverted. Same thing as well, a spelling issue. I provided links to the original production art that confirmed my change as correct bu the mod seamed uninterested.
Two Rs.
_ E _ R _ _
_ _ _ E R _ _ _ _ E _
Letters used: E, R
Which wiki was that?
Any S’s?
One S!
_ E _ R _ S
_ _ _ E R _ _ _ _ E _
Letters used: E, R, S
The Thundercats one.
Ok, so not the Thundercats-ho wikia than right?
No, I did update that wiki a while ago when I did my preservation of the Thundecats Ho VHS version, adding screen shots of the deleted footage.
The page I tried to edit was the “Enflamer” page, as I believe it should be the “Inflamer” page. I provided this pic, and the fact that the “Hear the Roar” book spells it this way too. Anyway, I don’t want to derail this thread but I thought i’d bring it up since the wiki was mentioned.
Any A’s?
One A.
_ E A R _ S
_ _ _ E R _ _ _ _ E _
Letters used: E, R, S, A