Lupo the Butcher
Lupo the Butcher was a minor character who was deleted from the game sometime prior to July, 1996.
The final version of the game and the beta build from September, 1996 contain level-select doors marked LUPO, but they are non-functional.
In the alpha build from July, 1996, the door is functional, but leads to the jaw area of Nupraptor's keep. It is unclear whether this means that Lupo was located in the keep, or if it is an outdated reference to a map section which was repurposed to be part of the keep after Lupo was removed from the game.
The NPC recording script available at Blood Omen Scripts has several lines on page 28 which appear to have been intended for this character. The Legacy of Kain Wiki has a more extensive description of the inspiration for this character, including the association between those lines and Lupo specifically.