The ultimate in potential energy.
This steel-and-uranium monster weighs in at a whopping 100 001 grams and is associated with Mortifer. You'll need serious Leg Strength to haul it out of the dungeon and back to Myrddin Wyllt. Boots of strength and belts of carrying with high enchantment are highly recommended for the task. A wand or scrolls of teleportation will be useful to 'skip ahead' between the staircases, especially if you are "Stressed" or worse.
As an alternative to carrying the bomb yourself, you can make a strong pet carry it for you. To actually get it out of the Pyramid, whoever carries the bomb must still be able to move, as teleportation doesn't work on the world map.
It is impossible to wield the thaumic bomb as an improvised weapon, as the required Arm Strength using both arms (over 6000) is far greater than the maximum possible strength stat that the player can achieve even through cheating.