Here is why I ask this. In past shows, we have seen pet dogs (for Archer) and cats (for Data), and I'm pretty sure that Captain Kirk had a pet bunny (even though it was never seen or mentioned). For Discovery, what if they go for a more uncommon pet and have one of the Discovery crew members have a pet monkey? The best thing is that the monkey can actually be useful in certain situations. It could help save the crew sometimes, so that it wouldn't be looked at as JUST a pet, but as another member of the crew.