Mary Shelley wrote Frankenstein, the Modern Prometheus in 1818 and the popularity of the book was such that by 1823 it had already been adapted for the stage. It was in this play, entitled Presumption: or the Fate of Frankenstein by Richard Brinsley Peake, that the origins of Ygor seem to have begun with the introduction of the character Frits, a bumpkin character who assists Victor Frankenstein in his ghoulish work and whose dramatic function is to provide a moral commentary on the work of his master (http://members.aon.at/frankenstein/frankenstein-theatre.htm). It seems that this character Fritz became a mainstay of the theatrical portrayals of Frankenstein, so much so that when Universal Studios bought the rights to Peggy Webling's theatre adaptation Frankenstein: An Adventure in the Macabre, and used it as the basis of their 1931 film (http://www.werewolfpage.com/other_creatures/frankenstein.htm), the character of Fritz also made the transition to the silver screen.
The role of Fritz, portrayed by Dwight Fry, was now depicted as a walking stick using, but nimble, hunchback who assists Henry Frankenstein in his body snatching and laboratory work. The character is a manic and sadistic figure who takes great joy in tormenting the monster and eventually meets his fate at the hands of the creature. It is also Fritz who, when sent to obtain a brain for the monster from the Goldstadt University, inadvertently steals the brain of a criminal and thus sets the monster on his murderous and misunderstood path. It is here that we see the original cinematic template for the character of Ygor first appear, however there were still some elements of the character that is familiar in popular culture still missing. Dwight Fry would also appear in the 1935 sequel The Bride of Frankenstein as Karl, one of two grave robbers turned assistants to Baron Frankenstein and Dr Pretorius in their creation of a mate for the monster. However neither of these characters were hunchbacks in the Ygor tradition.
Son of Frankenstein (1939) and Ghost of Frankenstein (1942).
Ii was in 1939 that the next step in the evolution of Ygor took place with the release of Son of Frankenstein. The film told the story of Baron Wolf von Frankenstein, the son of Henry Frankenstein who returns with his family from abroad to take up residents in his ancestral home in the village of Frankenstein. It is here that he meets Ygor (Bela Lugosi), the misshapen grave robber who has become a hunchback after a botched hanging for his crimes. As the story unfolds, Wolf, after finding the body of the monster, succeeds in reviving it, only to have it used by Ygor to murder all those who sentenced him to the gallows. The story comes to an end when Wolf shoots Ygor before saving his son Peter from the Monster, pushing the monster into a sulphur pit. Baron von Frankenstein then decides to return to his home overseas, handing the castle over to the good people of Frankenstein.
However, like the Monster, you can't keep a good hunchbacked homicidal maniac down. Ygor returned in Ghost of Frankenstein having survived Wolf von Frankenstein's bullets and the destruction of Castle Frankenstein by the villagers. In the ruins, Igor finds the body of the Monster (now played by Lon Chaney Jr) still encased in sulphur, and having dug him out, leads him through the country side to the town of Vasaria and the home of the second Frankenstein son, Ludwig. Ludwig is also a doctor, one who specialises in diseases of the mind, and eventually, through a series of twists, ends up unknowingly replacing the monsters criminal brain with that of Ygor's instead of that of his dead colleague, Doctor Kettering. As Ygor rises from the operating table, enjoying his new found strength, he suddenly goes blind as his new body rejects his brain, the monsters blood type being different than Ygors. The film ends with the Ygor/Monster setting the lab on fire, as he stumbles blindly in the flames smashing every thing he touches. From this point on Ygor and the Monster would be one, with his personality soon reverting to that of the mindless shambling brute it had been post Bride, albeit with seemingly restored sight.
House of Frankenstein (1944)
Although Ygor was now one with the Monster, it didn't mean that the stock character of the hunchback was gone from the Universal Horror series. With the hunchback's function being introduced by Fritz, his name being added by the character of Ygor, there was only one thing left for all the pieces to fall into place, the hunch backs personality. This would come in the form of Daniel (J Carroll Nash), the hunchbacked assistant of the Mad Scientist Dr Niemann (Boris Karloff), whose goal is to recreate the work of Dr Frankenstein. J Carrol Naish's portrayal brings to it all the things we expect from the role, the Peter Lorre-esque voice, the catch phrase of 'Yes Master', his work as a lab assistant and the vain hope that his master will one day build for him a new body. Here there are also shades of Quasimodo, as Daniel longs for the affections of a beautiful gypsy girl who in turn only has eyes for Lawrence Talbot, the Wolfman (Lon Chaney Jr). It is here in Daniel that the Ygor stock character truly manifests for the first time fully and establishes the model that many others would copy.
House of Dracula (1945) and Beyond
1945 saw the release of House of Dracula that once again featured a hunchback character, this time a female nurse Nina (Jane Adams) who works with this film's mad scientist, Dr Edelman (Onslow Stevens). However it was else where that the influence of the Universal Studios' hunchback characters began to show their impact and the Igor stock character began to feature. In the film House of Wax (1953), Charles Bronson played a mute but unhunched assistant called Igor. In 1962, Bobby (Boris) Pickett's Monster Mash album featured a song Irresistible Igor with other tracks on the album featuring dialogue by an Igor peppered with the 'yes master' catch phrase. The 1967 movie, Mad Monster Party?, a spoof which featured the voice talents of Boris Karloff among others, there was a butler/servant called Yetch (Allen Swift), who, although not a hunchback, spoke with a Peter Lorre style voice and addressed Dr Frankenstein with 'Yes Master'. The absence of a hunchedback in this character may have much to do with the fact that the Hunchback of Notre Dame also appears in the story, and to have two hunchbacks might have caused confusion. The Mel Brooks' tribute to the Universal Frankenstein films, Young Frankenstein (1974), also featured an Ygor (or is that Igor?) played by Marty Feldman, a who walked with a stick like Fritz, 'Yes Mastered' in the Daniel style and even had a moving hump that kept changing sides.
Transylvania 6-5000 (1985) had a whole family of Daniel-esque hunchbacks and the animated Igor (2008) featured a whole social class of Igors and tells the story of an Igor (John Cusack) who seeks to become a scientist himself. Things came full circle in the Universal Studios' tribute to their monster mash films of the 1940's, Van Helsing (2004) where Dr Victor Frankenstein (Samuel West) is assisted by Igor (Kevin J. O'Conner), a 'yes master'- ing hunchback with a treacherous demeanour, Fritz, Ygor and Daniel rolled into one.
At the end of the day it becomes clear that although some characters spring into fiction fully formed, others, like Ygor (or is it Igor?), are the product of gradual accumulation of elements in the public consciousness, something that is extremely obvious when we track the development of the stock character of Ygor from the theatrical addition of the bumpkin Fritz to the Frankenstein mythos in the 1820's, through the Universal Horror films of the 1930's and 40's to the films of the current era.