There was a time when Ghost Roaster was neither a ghost nor a roaster.  Instead he was a chef living in a village high in the mountains.  One day, while clipping wool from a sheep to use in a recipe, he accidentally fell into the Valley of the Undead and transformed into a ghost eating ghoul!  After eating an entire spectral village, its Ethereal Ruler chained Ghost Roaster to a spiked ball as punishment - its rattle heard as he wanders the night, warning nearby spirits.  When Master Eon eventually heard of his predicament, he figured even a ghost eater could be useful.  So he made Ghost Roaster a Skylander... after he promised to eat only evil ghosts.