To beat Terramorphous if you don't have Xbox live or don't like joining sessions, all you need to do is set up a split screen game with your main character and a second character. The second character's gear doesn't matter because he will not be involved in any combat. First, get to Terramorphous peak and have your second character drop into his lair without summoning Terramorphous. Far to the right of the horn you use to summon Terramorphous there will be a small ridge at the very corner of the map before the open cliff meets the rock face. If you run to this ridge you will see that you can crouch and walk out behind it, completely blocking all of Terramorphous's attacks. (Note: You can still do this after Terramorphous is summoned however it is much more difficult.) This character will serve as a placeholder so that when your main character dies you will not lose your progress facing Terramorphous and he will not regain all his health. Now when you are ready drop your main character down and summon Terramorphous. From there you may use any strategy to wear his health down, however I would recommend finding helpful Legendaries such as the Unkempt Harold and The Bee shield before attempting this. When you die, you will simply respawn and be able to drop back down and keep fighting Terramorphous without his health regenerating. If you do not want to lose money when you die, give it all to the second character (who will never take damage) first so that you recieve free respawns from the New-U station. Good luck and happy hunting!