Thinking about what would be the biggest gap in the mammal roster besides monkeys, obviously for me it'd be marsupials from a local zoo perspective but they're fairly well represented from a global perspective. I'd actually say it's probably glires, the group that includes rodents and lagomorphs - obviously we have no lagomorphs in the game at all, and only four rodents despite them being the most diverse of all mammalian orders. Of course the vast majority of rodents would not work as habitat animals, but I'd still love things like maras, agoutis, New World porcupines, a bunch of other SA rodents, more squirrels, cloud rats, Malagasy giant rats, springhares, rakali, etc etc.
The Nile Lechwe and Water Buffalo are some of my most used animals.
The water buffalo has been tussling with fallow deer for the spot of my favourite ungulate in the game for a while now, they're so pretty.
4. Australian monitor
5. Desert monitor (the biome not the specific species)
Perentie would give us both

