The Skull Pacifier is an object that originates from Hercules. It is a pacifier that has a skull-shaped nipple that had small spikes on the top. Hades used it by trying to put it into Hercules' mouth as a baby to get him to suck on it.
Everyone had given Baby Hercules a gift except one, Hades. When Hades appears on Olympus he goes up to Hercules' crib. He then offers the baby his gift, (which appears to be a terrible gift), a skull shaped pacifier that had small spiked barbs on the nipple. Calling the baby a "little sucker", Hades pinches Hercules' nose which caused Hercules to open his mouth, and tried to stick the pacifier into the baby's mouth. Just as the pacifier had almost went into the baby's mouth, Hercules squeezes Hades' finger which caused Hades to drop the pacifier. The skull pacifier is not seen again afterward.
The Skull Pacifier was an unusual pacifier that was Hades' gift to Hercules as a baby. The design of the pacifier was crudely shaped by Hades. The mouth guard was shaped like an ordinary bone. The nipple was shaped like a skull. What was even more noticing about the pacifier was the fact that there were small spiked barbs on the top of the nipple. It is often speculated that Hades wanted Hercules to suck on the pacifier so that the small spikes on the nipple would hurt the baby's mouth. It is currently unknown what would have happened if the skull pacifier ended up in Hercules' mouth.