Igor is a recurring set of characters in Terry Pratchett's Discworld series of novels. He, or they, is a member of a clan of servants from the region of Überwald, the members of which are all named Igor. The Igors are based partially upon Mary Shelley's Frankenstein's Monster, and partially upon the hunchbacked assistants in Universal and Hammer's film versions. While they are born in the normal fashion, the clan's strong tradition of surgery usually means that by the time they would have grown to maturity in the natural way many of their body-parts have already been swapped around repeatedly, mostly within the clan.

While they are extremely diligent in using their surgical skills among themselves they are also careful to share them among the people around their homes, possibly in a bid to make sure that when the torch-bearing mob comes along to kill the latest freak of science the resident Igor will be spared. Patients are, however, usually required to allow an Igor to have a "rummage around" for useful organs when they are about to die.

When an Igor suffers irreparable damage (which is hard to achieve in people who install back-up hearts and a lightning rod down their backs), they are usually "broken down for thpareth"; their functioning body-parts are distributed amongst those who need them and their brains are conserved until such time as another Igor finds a semi-willing patient with irreparable head-trauma, or manages to construct a suitable body from available parts. The Igors themselves describe the system with the words: "What goeth around cometh around." They have a strange ability to be at your side when you call them, and at a door before you knock. An Igor servant is considered a must by all members of the Überwald upper class, and, naturally, by any serious mad scientist.

The male members of the Igor clan traditionally lisp, are considered very good catches for any young lady, and their daughters tend to be very attractive ("Eyes on the same level, that sort of thing?"~Sam Vimes). The female members (the attractive ones) tend to not show their stitches, but share the talent of the males. They also don't generally lisp. Female members of the Igor family are named Igorina.

One Igor, considered "too modern" for Überwald by his family, went with Samuel Vimes to Ankh-Morpork. He now works for the Ankh-Morpork City Watch. He specialises in genetic experiments ("bio-artificing"), which, on the Discworld, simply involves very small stitching. This Igor appears in The Fifth Elephant, The Truth and Night Watch.

Another Igor shipped himself to Ankh-Morpork to assist Jeremy Clockson in building a glass clock, as told in Thief of Time.

When Magpyr family went to Lancre they naturally brought along their Igor, who has a dog named Scraps (or Thcrapth) that he built himself and who is more traditionally minded than his employers. See Carpe Jugulum.

A Borogravian Igor served in the Cheesemongers with Private Perks, in the book Monstrous Regiment.