anthro avian barkhaelle beak blue_body blue_feathers blue_fur brown_eyes claws collar delivery_(commerce) delivery_employee eyebrows feathered_wings feathers fur grey_body grey_feathers grey_fur gryphon hi_res letter letters looking_at_viewer mail mailbag male mythological_avian mythology postal_carrier postal_delivery satchel semi-anthro simple_background solo standing united_states_postal_service white_background wings zephyr_(bateleurs)