This is Mori's Shifter wand, a gift from Ferin Frost. Mori is one of surviving Shifters and guardian of the trees, Ferin found Mori as his dying father was giving him the protection and leadership of their herd and used part of his antler and main to make the wand. He saw Mori as a person than an animal and showed him the ways of magic to keep his herd safe and so a part of his father stays with him!
This wand might be in my Big Four at Hogwarts novel!
I think that Jack saw him as brother