When you wish for anything made of dragonhide, there is a chance that an incensed Tiamat shows up to kill you over it. The more things you wish for that are dragonhide, the higher the odds of this happening.

Replace Cavemen’s quest artifact with scales from the Chromatic Dragon (their quest then becomes “kill the dragon that is terrorizing our people” instead of “fetch the artifact from the dragon who stole it”). The scales only drop when she is killed, rather than her being generated with them (thus, they can’t be stolen). The scales could either be implemented simply as a base item akin to chromatic scales in UnNetHack which provide a cocktail of resistances, or as an artifact. If implemented as a non-artifact, the Caveman role will have no associated quest artifact.

The scales should NOT be enchantable into scale mail. The pile of resistances is good enough.

Chromatic dragon scales or scale mail, rather than providing all resistances at once, can be invoked to choose which one resistance it will provide. This resistance remains active until the next time you invoke it.

The Caveman quest goal level contains several dragon eggs of random colors beneath the Chromatic Dragon.