He has been nicknamed the "Cosmic Hobo" as the impish Second Doctor appeared to be far more scruffy and child-like than his first incarnation.
Mercurial, clever, and always a few steps ahead of his enemies, at times he could be a calculating schemer who would not only manipulate people for the greater good but act like a bumbling fool in order to have others underestimate his true abilities. Some times, this appears simply as a joke, but in other times, it seems much darker. But despite the bluster and tendency to panic when events got out of control, this Doctor always acted heroically and morally in his desire to help the oppressed.
This Doctor is associated with the catch phrases, "oh my giddy aunt!" and "when I say run, run!", and is noted for playing the recorder. In early stories he also demonstrates a fondness for hats and other types of headgear, mainly sporting a distinctive stove pipe hat when outdoors.