Transient would work from my end, since it's less a matter of "snatching" than of being snatched. Active things like talismanic magic (e.g. gris gris) or ritual effects don't have to require spirit involvement at all and could easily be explained away in the context of any form of magic wrapped in superstitious garb. The other end is spiritual possession, which does involve being inhabited for a short time by a spirit, and it is one of the more colorful aspects I was hoping to tap. It's short-lived (no more than a few hours) and not predictable at all - the spirit could impart knowledge, temporary power, or just ride the host for sport.