This is Eldon's dragon form, he is an immanent master, a dragon worshiper who can take a form of a dragon by using spells. He usually applies his spells before battles simply because his mighty dragon form boosts his strength and durability notably, also sometimes he uses just wing spells when he needs to reach high place and sometimes he uses just his size spell when he needs to move large objects and sometimes he uses just his tail spell so he could freak out people with it. The spells must be restored at altar of immanent mastery before being able to use them again. In full dragon form his skeleton structure is suitable to walk on 4 and 2 legs, he prefers to walk on 2 legs because he doesnt want to get his hands dirty and he needs them to carry and use weapons.

Check his other ref sheet for more info about him: https://www.weasyl.com/character/30817