The dwarf remains are the skeletal remains of Gilob, a dwarf who was killed on the lookout for goblins. His remains are discovered during the Dwarf Cannon quest. They are obtained from the watchtower south of the quest start point.
This is the first item by id number. As a consequence of this, dwarf remains may appear to occupy a variety of item slots that they are not actually in, such as the action bar or Grand Exchange offers, for a brief moment.