The kbd seems to be a mutant dragon that war forced away from his friends and family who live in the depts of the taverly dungeon.

 

The RuneGecko story:

As the others (the other dragons who thought he was not worthy of living with them) ran him out of the dungeon he took flight over falador and ran out of energy right before the varrok sawmill. As he hit the groud he vowed to get revenge on the dragons that ran him out of his home, the place where he was born. after he thought this he lost concience. He woke up to the sound of armour clanking, and footsteps getting closer to him. he looked up to see 3 varrok gaurds. he sprung up and with his fiery breath killed them all.

 

 he then decided to flee into the wilderness to the north, as he ran higher and higher into the wilderness he was attack by ancient mage, one however stoped and offered the dragon help. the dragon did not understand much but he did learn some things. he learned magics. he said thankyou to the kind mage and fled higher into the wilderness. he eventually reached a sort of temple. He asked a demon that was gaurding it if he could enter, the demon said yes. the dragon entered. and decided he would stay there, and wait for the day he could get his revenge.