The Doctor was forced to make his first regeneration when his original body finally wore out. His two companions, Ben and Polly, were understandably shocked to find a new man in the TARDIS, not only wearing the Doctor's clothes but claiming to be him. This surprise was only reinforced by the fact that this new Doctor acted nothing like the one that they knew.
In contrast to the grandfatherly first Doctor, the second has often been described as a "clown". He has an extremely lighthearted air, frequently breaking into large grins and even doing jigs on the spot. His initial penchant for disguises seemed to fade away later, but he made a very memorable washerwoman. The second Doctor also seems to get flustered very easily - when confronted by a difficult problem or cornered by monsters, he is just as likely to dither about it as he is to get on with business. In fact, sometimes he seems to have no self-confidence whatsoever - he often clings to his companion Jamie as much as Jamie clings to him! On such occasions, he is often heard to wail "Oh dear!" in a most piteous manner.
But, being the Doctor, there is more to this incarnation than the image he projects. Oftentimes, he exaggerates his helplessness in order to fool his enemies into assuming him to be a dunce, or to buy time. In fact, the second Doctor is quite sharp, and usually able to knuckle down and focus when he wants to (although this is frequently hampered by his having to shoo his companions away from distracting him). His unorthodox manner always produces results, giving the Doctor an almost smug satisfaction as he surveys his handiwork.
The second Doctor regards his travels with nothing less than joy. Little things make him extremely happy, and he could be totally content with simply sitting on the seashore with his bucket and spade. This sense of infectious glee often spills over to his companions, making travel in the TARDIS seem like one big holiday that is occasionally interrupted by nasty monsters.
Of course, when said nasty monsters enter the picture, the Doctor gets serious. But instead of planning and scheming, the second Doctor tends to make things up on the fly. His confrontations with villains and authority are less like shouting matches and more like the Doctor desperately attempting to persuade them to see the light. When the Doctor is in action, he works frantically to finish whatever he needs to do in the shortest amount of time possible, making him seem like a bundle of nervous energy.
The second Doctor is short in stature and a rather frumpy dresser - he wears a white shirt with checked trousers and a baggy black jacket, usually accented with a bow tie. At first, he tops off this ensemble with a tall stovepipe hat, but this is soon abandoned. His hair is usually rumpled, but he likes it that way. The Doctor often does his best thinking while tootling away on his recorder, and he is also the incarnation which developed the handy-dandy sonic screwdriver.
