Hello.
I have yet to see the ocelot. The lowland paca is almost always a no-show, same with our black jaguar. Both porcupines are very difficult to spot a well.
Oh, I am sorry, I did not say what zoo I was talking about. It was BioParque do Rio, formerly known as RioZoo (or the Rio de Janeiro zoo).
I forgot to add the sloth can also be a bit difficult to see sometimes. Same goes for the agoutis inside the walkthrough aviary.
I do, however, have another local zoo. Zoo VR, located in Volta Redonda, is way smaller than BioParque do Rio, though it still benefits from being close to said park.
The zoo's elderly Japanese macaque (which came from Rio) is truly a hit-or-miss. Close to him is the crab-eating raccoon (is it still alive?), which I have seen very few times, if more than once.
The animals in the big cat corridor are not hard to spot, but seeing all of them silmutaneously active is a moment to remember.
If you ever visit São Paulo, make sure to spend more time inside the frog and herptile houses. Their residents can be very difficult to spot. The irradiate tortoise was a personal challenge of mine, as I only got to see it on my last visit, less than two weeks ago.
The Brazilian canids (maned wolf, hoary and crab-eating foxes and bushdog) can also be no-shows.