This was one of the designs I created for the Gates of Discord expansion for EverQuest.
The backstory here is of a Dragon that lives in a dimension without light, and he enlists powerful creatures of different races to fight in his army. The floating glyph above his head was a concept I borrowed from Wayne Barlowe, of a powerful spell that was active and ready to be released instantly without summoning time, much like walking around with a loaded rocket launcher. It spells the dragons name and was granted by that Dragon.
The skulls represent different kings that were captured and killed, as a trophy and source of power to draw from when using magic in combat.
The leather panels that have spells inscribed on them at his back were supposed to animate and reconfigure to create a floating and rotating shield.
The spikes were poisonous Dragon Quills that could be launched at any time, much like the Yaka Arrow that Yondu uses in Guardians of the Galaxy.