“When the air is shimmering, you better run.
When the green fog crawls towards you, you better run.
When you hear the hissing of a scaly beast, you better run.“
Imperial viper dragon sketch for worldbuilding. Vipers spit very aggressive acid or lye. Some even spit explosive or poisonous gas. They are not used on battlefields as they are also dangerous for allies, but used as general defence, for traps or to secure a retreat.