In Twelve Monkeys, Cole hears someone who calls him as "Bob"... He hears him in the past and also in the future... Who or what is he?
In short, there's no definitive answer to this question. The film's themes of psychology and chaotic treatment of time travel make it difficult to pin down a solid answer. Still...
The voice Cole hears calling him Bob is mostly unexplained, but the homeless man he and Kathyrn run into multiple times shares the voice. While it is unlikely that this man is the sole source of the voice (as Cole hears it several times before when escaping the mental hospital, and at other points where it is incredibly unlikely the homeless man is around), the confusion and mental degradation caused by repeated time travel (or the medication in the mental hospital) throughout the film is hinted at as the source of the voice. Keep in mind that the first place Cole hears it is while strapped down after his first return to the future. Cole may simply be imagining it because he has started to go insane, an interesting contrast to the dramatic irony produced in the audience, who know that Cole is sane about being from the future.
Nonetheless, the voice does seem to perform a Donnie Darko-like role in driving Cole's actions as another personality only he can hear. As Cole can be thought of as the "monkey" (in reference to the monkey sent into the well to retrieve the kid, but instead taking the sandwich, much like Cole is only back in time to find a sample of the virus, not stop it from spreading), there's a possibility he is being used as a test animal by the scientists. To support this piece of speculation, note that the virus first breaks out in the airport where young Cole is. Odds are, if he weren't immune, he would have died, but even if he weren't (and built up an immunity after being exposed to the virus), he would have lived through the virus outbreak, and probably had it at one point. Unless the scientists had a way to rid a person of the virus (which would negate the need to send somebody back to begin with to get a sample), the sanitation procedures the scientists are putting on are all a show, and everyone still alive is infected, with an immune response keeping them unharmed.
If Cole is a test animal, it is likely that it is for time travel itself, as the procedure seems unrefined (they send him to the wrong time frequently). Thus, he may very well be receiving brain damage from time travel (if not already from the stress of the events), and the voice may be a product of that fact. One other explanation is that somebody from the future is somehow observing and speaking to Cole during his ordeal, which isn't out of the question either. Otherwise, it has a supernatural explanation.
The voice that calls Cole "Bob" seems to be a communication from the authorities in the future. First the voice interrogates, then it manipulates, and finally it is hostile:
-In its first scene, the voice interrogates Cole, asking him what happened during his time travel. "Hey, Bob, you do the job? Did you find out the big info?...Army of the Twelve Monkeys...where the virus was prior to mutation?"
-In its second scene, the voice seems to suggest to Cole that he wants to return to the future, and stay there. "To see the sky -- and the ocean -- to be topside -- breathe the air -- to be with her. ... Isn't that right? Isn't that what you want?"
-In its final scene, the voice ominously reminds Cole -- just before he is killed -- that he is not allowed to stay in the pre-virus world. "Point of fact -- you don't belong here. It's not permitted to let you stay."
12 Monkeys follows the structure of a Greek tragedy, with the idea of hamartia - a sort of mixture of fate and human fallibility - literally 'however much you try to escape, you are always there'. In traditional tragedy, there is always a chorus who reminds both audience and protagonist of this at key intervals, known as episodes or interludes, as well as commenting on the action and how it is affecting the protagonist and moving things towards their inevitable conclusion. 'Bob' is the chorus.
After seeing Gilliam's new film, Zero Theorem- I believe the mysterious voice in 12 Monkeys to be 'Bob' from Zero Theorom. He is introduced as Bob and that he calls everyone else Bob because it's quicker and uses less memory. He is also the son of 'Management' and seems to know an awful lot about what's going on...all of the time....
Well, I was thinking, maybe it was Cole himself. Come of think of it, Cole removed his teeth too, right? And the old man had his teeth removed too. He always knew what Cole was thinking, because he probably had been through it. He thought the same things because he is Cole himself, now an old man and he knows what the young Cole is gonna think about.
Cole says something about 'dimensions' while he was being interrogated ny scientists in the future. Maybe the old man Cole came from a parallel dimension where he and Railly actually went to the Keys and lived their life. Or whatever, just ultimately, he survived, grew old and went crazy all the time, probably because he couldn't get the images of adult Cole trying to gather information or young Cole witnessing the airport scene.
Though I can't understand...why Bob?
I think the overall theme of this movie is that fate exists and any attempt to subvert it will only backfire. I think the Bob voice is a symptom of his insanity and his repressed guilt as, on some level, he feels responsible for the end of the world. I think it ultimately serves to preserve ambiguity concerning his insanity, probably for entertainment. That aspect of the movie and in prison Jose's lines about the volunteers "You don't know that. Nobody knows that. That's just a rumour, I don't believe that." I think play in a role into a greater theme I haven't been able to dissect. If there is another theme to the movie it is that we are all insane.
I thought that the man in the mental hospital wearing the suit and the bunny slippers was the voice that called Cole bob. But I can only base that on the tapping of his foot. In the scene where we see the man in the suit in the mental hospital he explains that he is not from outer space etc. After he is finished telling his story there is a close up of his foot tapping.
At the end of the film when Cole is hearing the voice again in the bathroom you see a man in de toillet tapping his foot as well.
I know this is pretty far fetched but it also really stood out.
Bob is ambiguous and up to the viewer, I like to think of Bob as fate personafied and it has capacity to be anywhere and anytime. Also a tinge of karma for the human race, it has a mission to rebalance human Vs earth war and nothing will change it. Essentially Bob is the Cassandra virus with a voice, capacity and tenacity to make sure it's plan to reduce 80% of the human race succeeds.