Munkustrap's the leader, the alpha of the Jelicles, so to put it, 
while Deuteronomy's away. That much is obvious.

He's a charismatic kind of cat, one that's near and dear to all, but 
he's also farily biased and rigid when it comes to certain peoples, 
shall I mention any names??? (Grizzabella). He not only dislikes her 
personally but sees to it that no one else has the chance to go near 
her.

From his collar (in the movie) it seems that he lives in a house, not 
on the street, and my friend has a theory that he, Quaxo 
(Mistoffeles), and Rum Tum Tugger share the same home. I think that 
describes their companionship and strife a bit. While Munkustrap is 
the leader of that little trio, RTT seems to be a close second, which 
explains Mu's respectful tone towards him. And as for Quaxo...those 
two seem as tight as kittens, to me.

He's a neat cat. A good leader. What more can be said?

- Raiden