Ebony is a white tiger, from orc lands.  She was found by Asa in one of his trips to the orclands, as a kitten, sick and alone.  Asa was nursing her back to health on his visit to kyrene.  Davis instantly felt for her, and took care of her.  Asa quickly saw that Ebony was in good hands and "gave" her to him for Asa's 15th birthday.  She became his second real friend, after Amara, and helped fill the void created when Amara went to training when they wre 14.  In Pangea, tigers are native to orcland, and are rare to nonexistent in human territory.  Asa gave him what advice he could about caring for her, and Davis figured it out from there.  She quickly became not only a friend, but a defender, growing from a kitten to a 700 pound, 10 foot long behemoth (these are slightly exagerated charateristics of a male tiger).  She added an extra level of muscle and intimidation protecting him from bullies.
She despite the fact that her personality is clearly that of a "lap cat"; she sleeps 18 hours a day, grooms for about 2 a day, and spends most of the rest of the time just watching things.  She is also happy to get petted or groomed most times.
She is unnaturally smart, and more aware than she appears, being the typical "intelligent pet" from stories, aware of threats to Davis and reacting appropriately.
She plays two roles in the story; a friend for Davis to relax with, comic escape, adding occasions of whimsy, and muscle, acting as an additional bodyguard for Davis.
In order to protect Ebony, Davis has given her a powerful magical amulet, protecting her from hostile magic attacks, worn tightly around her chest.  Worth a small fortune, it makes her invulnerable to most direct magical influences.

Role:  Tiger, pet
Story Activities:  Ebony is mostly companion, defender and stress relief for Davis in the story, occasionally engaging in individual mission/activities that suggest she is an extremely smart cat.  She has a daily excercise period, where Davis or one of his most trusted staff run her through an obstacle course, designed to keep her fit and work out her energy.  Sometimes pretending to resist, once she starts she enjoys it.
I'm toying with the idea of having her "courted" and eventually mating with one of the gryphons at Dreamhaven.  They are after all, part lion.  I always felt bad for her, being basically alone in her species.  The gryphons could give her playmates, and even a mate.  We'll assume they mate for life, and are very fillial, committed to each other, and their offspring could be very interesting.