Vladimir (affectionately known as Didi; a small boy calls him Mr. Albert) is one of the two main characters from Samuel Beckett's Waiting for Godot.
This would explain his constant references and his attempts to engage Estragon in philosophical and religious debate.
Vladimir is deeply concerned with appearances and goes to great lengths to make sure Estragon behaves so that his own dignity is preserved.
He is something of a pack rat: he carries all the food the tramps have (though he never eats himself), and has other (to quote the play) "miscellaneous" junk in various pockets.
He suffers from a venereal disease that causes him pain in his genitals and a need to urinate when he laughs.
This might indicate a sexual past: he refers to a woman he knew who "had the clap"...although it is unclear whether this is the cause of his current condition or not.
Vladimir has the only social conscience in the play (compare Estragon's misanthropic view of humanity: "People are bloody ignorant apes!
"), and it seems that he cares a great deal for the plight of his fellow man: he expresses outrage at Pozzo's treatment of his slave, Lucky, and acts as something of a parental figure to the sometimes childish Estragon.
He hates dreams, as they represent a cruel false hope, and he is unable to cope with Estragon's logic, the simplicity of which throws him off.
He also does not suffer fools well: Pozzo's decadence and Estragon's crudeness give him much cause for indignation.
He has been portrayed by many notable actors, including Burgess Meredith (with Zero Mostel as Estragon) and - in one rather notorious version of the play - Steve Martin (with Robin Williams as Estragon), Patrick Stewart opposite Ian McKellen, and Alex Winter (opposite Keanu Reeves).
It is true that when with folded arms we weigh the pros and cons we are no less a credit to our species.
^1 "When Burt Lahr as Estragon in the American production insisted he was 'top banana' and warned Tom Ewell as Vladimir, 'don't crowd me,' the balance of the play was disturbed.
Alan Schneider reported Beckett's response, 'Beckett assumes Vladimir is his major character.