[ Appearance/Biology ]
This incarnation of the Doctor has brown eyes, and wears a long brown trench coat (supplemented, usually, by his blue pin-striped suit). He has a mole between his shoulder blades and he has often been taken up on his rather skinny build. On regeneration he was happy to have hair longer than his previous incarnation, but seemed somewhat disappointed by not having ginger hair. The dark brown hair he does have, he takes great pride in. He has worn it in several different styles throughout his time, from having it to a fifties style quiff and having it flattened forwards.
On rare occasions he has been seen wearing a Tuxedo, the only other attire he has been shown to wear, along with his blue suit with red pin-stripes. His suits are generically worn with a shirt and tie, which are always seen which either two of his suits, and his light brown coat. He wears trainers, or more specifically - Converse All Stars. He seems to have different colored trainers depending on what suit he's wearing. Cream to go with his brown suit, black for the tuxedo and burgundy for his blue suit. Another, more notable piece of attire are his dark turquoise shell rectangular glasses in which he has named them "Brainy Specs". Although he has used them on many occasions he once admitted that he doesn't need then, they just make him look smarter.
Gallifreyans have Triple Helix DNA as well as TNA. The extra third strand was added by Rassilon to make regeneration possible. Regeneration was created to extend the already amazing Gallifreyan lifespan. Their bodies are filled with self-replicating biogenic molecules (sometimes known as the Immortality Virus) that work ceaselessly to repair and prune damaged and malformed cells. Because of this, it takes hundreds of years for a Gallifreyan to show signs of aging. After healing, the regeneration proceeds and the subjects' body (and to a lesser degree, the mind) will be completely restructured.
Within the first 15 hours of regeneration, a Gallifreyan will still have enough residual cellular energy to regrow a severed body part, such as a hand.
The biogenic molecules are aided by the temporal platelets which cluster around any wound, accelerating time in that area to speed the healing. A broken leg can heal in anywhere from a few hours to 4 days depending of the severity of the break. These rates of healing can be enhanced if the Gallifreyan is kept near (or inside) a TARDIS.
Despite looking like humans from Sol III, Gallifreyans have got multiple organs of virtually everything including two more ribs (than humans). They have 2 of most of the organs that humans have only one of, and four of the organs that humans have only two of. Aside from the extra ribs, a Gallifreyans skeleton is almost identical to that of a human being.
Gallifreyans have more than one stomach and are not as vulnerable to malnutrition as humans are. Some (if not all) believe that only one meal a day is perfectly normal. They can easily go two days without water and a week without food is not a major strain - infact, they sometimes sit in thought for days without food or water. However, 40 days without food or water will make a Gallifreyan delirious.
Arsenic is toxic to Gallifreyans and will inhibit their enzymes. If a large source of protein, salt, and other chemicals (found in ginger beer) are available, a Gallifreyan who has been poisoned with arsenic can use a major shock or surprise to trigger detox. This detoxification allows their stomach to stimulate inhibited enzymes to reverse and release all toxins as gas that can be exhaled. Aspirin is incredibly toxic to them, as well.
Their skin smells like honey and has extra subdural and subcutaneous layer. This makes their skin very resistant to radiation, physical damage, poison ivy, sunburns and tanning. Gallifreyans can resist radiation that will kill a human in 4 minutes for 2-12 minutes before they start to take noticeable damage. Incarnations which appear to be physically younger are significantly more resistant to radiation then older bodies. They also have incredible strength for their size.
They can enter a self-induced sleep trance in which breathing, heart beat, and brain activity are all reduced to an absolute minimum. While in this trance a Time Lord can ponder complex ideas without any outside distractions. 20 minutes in this state is equivalent to 8 hours of sleep for a human. Thus, they only need about 1-6 hours of sleep every 2 days.