Rip off the standard Immunity to Magic like so? Check the italicized bits!
Immunity to Magic (Ex): A death mold is immune to any spell or spell-like ability that allows spell resistance. In addition, certain spells and effects function differently against the creature, as noted below.
Cure Wounds spells stun a death mold for 1 round per (hp the spell would have healed/spell level ???).
A delay poison spell dazes? a death mold for X rounds.
A neutralize poison or heal spell kills a death mold instantly (on a failed Fortitude save?).