The Thumgog's name is Bacaata, if remember correctly
Btw. any of you remember that two gates at the very entrance to Scotia's Castle (after finishing the war with one of the weird races and helping other) that can't be opened, entered or bashed, but where it was visible there's something behind them? The weird thing is, you aren't supposed to enter them in the game oficially at all, BUT you can. All you have to do is to save the game, exit it, hexedit the savegame on the location where the position of the group is saved (little experimenting needed there, easy way is to save the game, move to the next tile and save another game, then compare the games in DOS) so you end up now BEHIND the gates.
The bonus in that - there a pretty cool two-handed sword you can get there, not as powerful as best one you get on usual way, but almost, and it has another name. Now the question is - why would that sword be there if the player isn't supposed to be able to reach that place...