After several minutes of this, Xion got frustrated and decided to risk one spell. She charged in, got in close and then "FIRAGA!" she yelled blasting a powerful fire spell at the thing's underbelly, point blank. She rolled out from under it in case it fell on her, since these things for some reason didn't vanish when they died. Hopefully this one at least dropped a potion or some munny or a healing orb....