Karmic creatures

Related:
* Suicide attackers - often the payload the suicide bomber is carrying explodes when they die.

The karmic bit refers to them bringing bad karma for anyone who dares attack them.

Originally intended for cases of "final retaliation", such as creatures expelling a cloud of noxious fumes, their acidic blood splattering about, exploding, or even for types of "glory" devices that have the intention of taking out whoever manages to defeat the person carrying it (e.g. the wrist devices Predators have). One of more literal cases would be a robot that has active electrical current going through its hull, so hitting him with bare hands would electrocute you.

Examples:
* Player is electrocuted, burned, poisoned, etc. if they attack the creature (usually by melee weapons)
* The creature explodes on death, emits poisonous fumes on death, places a detrimental status effect on the person who killed it, etc.