Death's Soul Rings are 3 strange gold rings with supernatural powers and titular objects in the Regular Show episode "Dead at Eight". They are rings of Thomas' past babysitters that did not do a good job. Hence, [Death (Regular Show) Death] put their souls in rings and kept them.
The Soul Rings are gold on the outside, black on the inside, and a different colored spirit in the middle. The colors of the spirits are orange, green, and blue.