|It's never explained in the movie, it's just left to the imagination. I saw the movie numerous times & finally googled it one day to see if I could find the answer. There's a lot of theories out there about it but I think Tarantino claimed it was a "MacGuffin". |
The explanation I liked best is that it was supposedly Marsellus Wallace's soul & he was trying to get it back. When you look at it that way, it puts a whole different spin on the movie.
"If my answers frighten you then you should cease asking scary questions" - Jules Winnfield (Samuel L. Jackson) in Pulp Fiction