What do dragons not like?

Dragons are significant eaters and may eat huge meals at a time, consisting of wild animals, cattle, and even humans.

All member of the Class Hexapedal are resistant to heavy metal poisoning and use whatever metal oxides they have in abundance in their scales for displays. In the higher dragons (Weir-drags, Sore-drags and the true fire dragons) this tolerance has developed into throat plates that serve as catalytic surfaces on which to ignite their flammable poisons. Some of these creatures will even go about gathering and hording heavy metals. Such habits have resulted in open conflict with other creatures doing the same thing. -Note: this is only in one fictional universe.