Personality: Iivari is Conner's 'saviour' and mentor, adopting the elf boy at a young age and grooming him to fit into his own image of an ideal protégé.  While appearing kind, whimsical, and never without a smile on his face, Iivari is, in reality, cruel, cunning and not afraid to destroy anyone or thing that poses a threat to his goals.  Having deep seated hatred for the Elven race, Iivari does everything in his power to exact vengeance on them; at one point invoking war on a peaceful village of elves, of which Conner once belonged.  Although he was responsible for the death of Conner's family he seems to harbour feelings for his apprentice.  His facade of niceties will often crack around Conner and reveal a somewhat softer and affectionate side. 
Iivari is a rabbit of small stature, as most tend to be, standing at about 5'0".  His physique is dainty and elegant, though his hands and feet are larger proportionately, with fingers and toes that are long, graceful and end in small sharp claws.  He also has well muscled legs which he disguises with layers of poofy fabrics and tall boots.  His skin tone is pale grey mottled with large indistinct spots of darker grey, most notably over his eyes, towards the tips of his ears, hands, feet, and down his spine.  The mottling often appears like freckles in other places on his body, including his light, fluffy bunny tail.  Iivari has large floppy ears that go past his shoulders and are covered in soft, short fur that creeps over his skin.  It can be difficult to tell where his the fur ends at most times.  Iivari also walks on the balls of his feet, whether rabbits do this out of choice or evolution is unknown, it does not, however, add any height to him, as he is never seen flat-footed.  He carries with him at all times some kind of large string instrument.
Commission's Notes:
Iivari is a Sound Mage and as such he uses music, spoken word, poems, humming, and singing to cast his spells.  Sometimes these spells hold their own special effect (like evoking an elemental spell) while other times he uses the raw power of sound waves to do direct damage.  He can also 'throw' his spells, much like a ventriloquist throws their voice, dealing damage or casting magic from a distance.  This indirect way of using magic reflects his personality, which is under-handed and never as it seems.  I'd like this to show in commissions of him, personality is paramount.  The costume is less important, as long as the general idea of fabulous-ness/minstrel is communicated.  Do whatever you like with the design.