Senior don your hunter’s cloak. - 10 years old, could be considered a "senior". [I don't think you're old Crowley. -petspats-]
Its colors will shine bright through the trees while we hunt for blood. - Possible reference to his coloring. His stripes are bright. They could also refer back to the hunter's cloak line.
Mount your horse and bring the beagles. Didn’t I tell you to bring your other half? - Reference to his Hellhound companion. When googled, Talbot is also a kind of Beagle.