The creature called Gloo was created by criminals in an attempt to clone the first Jack-in-the-Box, some time after the hero's death. Their goal was an ultimate henchman, but they wound up with a nightmare. Gloo turned out to retain some echo of Jack-in-the-Box's sense of justice, but a warped and twisted version of it, and the creature began to hunt and kill criminals. It frequently employs grisly, macabre methods of murder that its skewed mind considers funny; horrific variations on known practical jokes and clown antics. As with his drive for justice, this behavior seems to stem from a distortion of the real Jack-in-the-Box's essence. Non-criminals are not necessarily safe from it whimsy, either. In its insanity, its ability to discern the bad from the good is not always the most reliable or sensible.
Gloo has the ability to shoot acid and other toxins from his body. His liquid form enables him to smother victims and form multiple tentacles/limbs, as well as withstand to bullets.
Among the many names in its long list of victims are the members of the Crazy Eight crime gang.