You said to go crazy so I might... be warned
Note to self:
-standard
missing limbs, horns - light colored tails, no vivid colors or multicolored tails - different bone/horn structure - longer neck fur
-uncommon
brighter tails/horns (multicolored) - extra horns - glowing vents - halo around head/tail area (only one) - pupil shape
-rare
vivid tails/horns - horns on body - wings (one set) - two halos (around head/tail area) - more vents - extra limbs (tail included)
-legendary
magic vents (elements generated from it) - elemental powers - halos around body - multiple halos - multiple wings - neon tails/horns - no neck fur