Magic is quite a valuable resource in the magical world, which every time becomes more difficult to use. Previously, magic was very often used to move and transport everything you need, but in the last century magic has become not enough even for it. At this time, the TRUP project arose, which studied the interaction of the negative magic of a corpse with the magic of a living being. In the course of experiments, it turned out that when the magic of a corpse was mixed with the magic of a creature, much more magical energy was generated. This allowed the creation of robotic corpses that were, one might say, eternal. They did not need sleep, food, they could carry any amount of cargo (as much as the structure could allow), and their permeability was much higher than that of all other creatures.