School necromancy [poison]; Level blue 8

This spell functions as monstrous poison I, except that the monster whose poison you're recreating must be CR 17 or lower. If your target fails its initial save against the poison, the poison cannot be cured normally; no number of successful saves stops the poison from running its course (though each successful save otherwise functions normally). The only way to cure the poison prematurely is to use neutralize poison or a similar effect.

The DC to remove the poison with magic is equal to the save DC + 5.