Nutt is an Orc. He was found and freed by the Reverend Mightily Oats from the village in Uberwald where he was chained for seven years to an anvil in a forge. Nutt marks his birth from this point, the point when he was helped into the light. In the forge, he picked up some smithing and demonstrates a remarkable ability to shoe normally recalcitrant and dangerous horses. He was presumably brought by Oats to Lady Margolotta, who taught him that he must be becoming and attain worth. This caused him to develop a complex and during the events of Unseen Academicals he regularly asked the question "Do I have worth?" He spent much of his time in Lady Margolotta's library where he read quickly and voraciously, to the amazement of Miss Healstether, Lady Margolotta's librarian. He has a tendency to liken situations to those described in philosophical texts, and seems to generally assume that everyone else is as well-read as he is.
He was sent by Lady Margolotta to Unseen University in Ankh-Morpork where he worked in the candle vats as a dribbler, a job that he said he enjoyed. While at Unseen Univeristy he becomes the coach for the Unseen Academicals football team after impressing Ponder Stibbons with his knowledge and skills (or possibly because Ponder Stibbons was just happy to delegate one of his thirteen jobs to someone else). Nutt befriended Trevor Likely (who nicknamed him Gobbo, short for Goblin because that is what both believe Nutt is) and Glenda Sugarbean, and as of the end of Unseen Academicals he is romantically involved with Glenda.
Nutt did not know that he was an orc for most of Unseen Academicals and believed that he was a goblin, having shut the information behind a metaphorical door in his head. He eventually opened that door with the help of Glenda and Trevor, by psychoanalyzing himself under hypnosis. Throughout the book he is followed by the Sisters of Perpetual Velocity, who have been sent by Lady Margolotta to stop him from killing or injuring anyone should his "true" orc nature manifest itself unexpectedly. On discovering that he was an orc he fled, planning to return to Uberwald. Glenda, Trevor, and Juliet Stollop chased after him by coach and caught up with him in Sto Lat, where they convinced him to return to Unseen University; he grows more comfortable with his race and in particular his strength (for example when he breaks into the Palace, Vetinari asks if he tore the gates bodily from their hinges and is told that Nutt lifted them bodily from their hinges and stacked them neatly in the courtyard.)
Nutt takes over as Unseen Academicals' goalkeeper during the Ankh-Morpork United match after the Librarian is poisoned. He is a successful goalkeeper, although the game is really won by Trev Likely's impressive tin-can skills, after some quick thinking by Glenda.
After he psychoanalyses himself, Nutt claims, "I am an orc with a terrible urge to smoke a cigar". This could be seen as a parody of World of Warcraft as certain Orcs can be seen with cigars in some screenshots, although considering that Nutt had just finished psychoanalysing himself, it is more likely a reference to the famous phrase 'sometimes a cigar is just a cigar,' generally attributed to Freud, although it does not appear in any of his works.
The "closed door" subplot in Unseen Academicals relies almost completely on psychoanalysis parodies. Nutt brings a chaise longue (fainting couch) down to the candle-making area where he works, and subsequently uses it as the location for his hypnosis. He requires Trev to spin his shiny can in front of Nutt's face, mimicking the popular music hall hypnosis trick, usually done with a watch. Nutt also lapses into an Uberwaldian accent during his self-hypnosis, and explains to Glenda and Trev that this accent relaxes the patient, again harkening back to Freud.