Most of what will eventually be hosted here, with the exception of Folksy Facelift, Vanilla-Friendly Fixes and some miscellaneous downloads, can be split into three separate categories, based off of the formats of what was provided by Blue Fang when the game was being actively developed.
Zoo Tycoon 2: Marine Mania (2006), © Microsoft Corporation
Typically very large, offering between 20 and 30 animals, at least one new building/scenery theme with some general additions on the side, a healthy amount of new foliage, a few new maps, new challenges, between 1 and 3 new campaigns and - in the real crème de la crèmes - novel, game-changing gameplay mechanics.
Four expansions were released under Blue Fang:
Endangered Species spotlighted threatened animals and conservation success stories and introduced tour vehicles and elevated paths to the game
African Adventure offered a slew of charismatic African wildlife and improved animal behavior but was generally extremely bare-bones (no new foliage, a single three-scenario campaign, no new additions to gameplay...)
Marine Mania was all about the ocean and went all-out with expanding the game to accompany its creatures (brand new biomes, tanks, marine foliage, Seaworld-style shows, player diving mechanics, etc.)
Extinct Animals brought a heaping helping of extinct wildlife and three new minigames accomodating them to the table.
Coming eventually! Hopefully, maybe.
New World Wonders (2026), by NanoLancensis
An intermediary between an expansion pack and a premium download - adventure packs contain up to ten animals alongside a helping of landscaping and construction options.
There is no precedent for anything akin to these in Blue Fang's gameography, maybe barring the Endangered Species Theme Pack for the original Zoo Tycoon, so I can't give any proper examples here.
Coming 2026
Yee-haw! Zoo Tycoon 2: New World Wonders grants zookeepers the chance to house ten awesome animals from North and South America in their zoos, including the pronghorn antelope, American alligator, greater rhea and giant anteater.
Zoo Tycoon 2: Dino Danger Pack (2006), © Microsoft Corporation
Alternately a mini-pack, content pack or deluxe download - they bring four, five or six new animals to the table, among a reasonable amount of new content (e.g. fences, enrichment, foliage, maybe some scenery).
The Dino Danger Pack was the only official example of this pack type, offering four dinosaurs, a new challenge and scenario, a king sago and dino-friendly food, fencing and enrichment.
Hopefully it goes without saying that, at Nano's Zoo 2 Zone, "premium" doesn't mean "paid!" It's just a fancy title for download packages that are bigger than your average one.
Coming eventually!
Musk Ox & Tundra Theme Pack (2005), © Microsoft Corporation
The smallest possible package for a download - at largest, the original bonus downloads comprised of one animal and a theme pack or a decently fledged beautification pack, and they got as small as one animal with nothing accompanying it and a pack including four guest variants and a drinking fountain.
A total of nine official bonus downloads were released (discounting the Asiatic black bear), from the Black Leopard & Stuffed Prey Dummy in November 2004 to the Holiday Pack in December 2005, to the website-exclusive Addax at some point in mid/late 2006. There were evidently plans for other downloads, but none of these materialized.
A collection of UBDs, split across a few separate pages, can be found on the dedicated Downloads page. Below are some inaugural Nano's Zoo 2 Zone downloads:
Spices up the paleo-experience with three new ancient animals to complement the original thirty: the Columbian mammoth, Irish elk and Embolotherium.
June 21, 2021 (Download)
The youngest and most northerly species of Pachyrhinosaurus is now available for adoption - and for excavation, assembly and de-extinction - in your zoo.
September 5, 2023 (Download)
Zoo Tycoon 2's grand finale was supposed to have more than it did, and this booster pack is here to fill that void, even if only a little bit.
May 25, 2025 (Download)