A friend of mine from Serbia once tried to replicate the sound of Swahili when he listened to two girls from Kenya speaking, and managed to say "Wewe kuku nono". They were furious.
I noticed "kuku" on the hints is listed as "chicken" and "chickens" which would make "kuku" n-class. I verified as much with a dictionary. Wouldn't that make the correct phrase: "kuku nzito"?
It's n-class animate, which makes it decline as n-class nouns, but since it's animate, it takes m/wa-class concord, with some small modifications. Don't remember which, but "Kuku mzito" is correct, when you are talking about a live chicken.