Noo-Noo is the hoover (American:vacuum cleaner) for the
Eloi Teletubbies. As they are pretty much incapable of doing much of anything useful, the crap jobs are left for Noo-Noo. However, it is suspected that Noo-Noo is actually there to subtly direct and supervise the Eloi Teletubbies for god-knows-what purpose, aided by the voice trumpets.
There have been times when Noo-Noo has gone rogue and was secretly replaced. Most people know of the hat-stealing incidents with Dipsy, but are not aware of the missing orange Teletubby, Flopsy, sucked up during Spring cleaning and never seen again. It is speculated that rogue Noo-Noo is always aided by several thousand clones of a mysterious Agent Smith in both housecleaning and deleting characters. For stubborn and uncooperative creatures like Flopsy are not tolerated in The Matrix, the massive virtual Nanny State owned by Disney and Nestlé.