Very little is known about Doctor. He's kind, likes to help others, and has a weird sense of humor. Everything else is unknown. No one even knows his breed. Although, he kinda looks like some type of shepherd mix. Doctor has quite a lot of friends, yet is most often seen traveling around with Echo. He has traveled to so many timelines that he practically has friends in every year.

Doctor doesn't need the assistance of any physical object to travel through the galaxy, but he does when he takes others with him. He can command any object as a traveling key, as long as he and his partner are both touching it at the same time. Because most others tend to...let go of what they are holding on to while they whip through space and time, Doctor has adapted to traveling with his guests in closed compartments or vehicles.