i am wanting to know what a terminal (final) object in the coslice category

$\displaystyle (A\downarrow Set)$ might be (technically, where "A" is the functor:

$\displaystyle A:1\rightarrow Set$ and where the other functor of the comma category is

$\displaystyle id_{Set}$

alternatively, if it is easier to explain this as an intial object in the slice category:

$\displaystyle (Set \downarrow A)$, that's fine as well.