ToME: the Tales of Maj'Eyal

Ran into an issue using Animus Purge that would kill a splittable (green slime) - the slime split, neither became a husk, but both splits became literally un-killable - they take damage, but they don't die at any HP total no matter how negative. I re-husked one of them, and now they just sit there, hitting each other until the end of time (or until I exit the zone never to return, I suppose), with negative HP totals. I almost feel bad about leaving. Further splits from these - don't ask me how this can even happen, but I split a third sitting there lobbing spells at them - are also impossible to kill.
Edited to add: The husk follows me around through zones, soaking up infinite damage. The only way to get rid of it was to Husk something else in a new zone.