I am aware that I am posting this after 2023... but this seemed fun to post what I've seen and where, to my best recollection. I have limited 'substitutions' otensibly to the subspecies level.
Base Game
Aardvark - London Zoo [2016], Chester Zoo [2019], Whipsnade Zoo [2023], Longleat [2024]
African Buffalo - Depending on if nanus is not a species in its own right I first saw this one at Marwell in 2017 and again in 2020; and at both Berlin Tierpark and Zoo in 2022. If nanus is a species in its own right, I have seen Cape Buffalo at Berlin Tierpark
African Leopard - Wildkatzenzentrum Felidae [2022]
African Savannah Elephant - Tel-Aviv Safari [2016], Howletts [2019] ... don't think any more
African Wild Dog - London Zoo [2016, 2021], Chester Zoo [2019], Berlin Zoo [2022], Whipsnade Zoo [2024]... maybe others
Aldabra Giant Tortoise - Cotswold Wildlife Park [various years], Bristol Zoo [2017, 2018, 2022]
Amazonian Giant Centipede - no idea if I've ever seen this one
American Bison - Berlin Tierpark [2022], Berlin Zoo [2022], Woburn [2024]
Bactrian Camel - Too many examples to list... last seen at Longleat [2024]
Baird's Tapir - Never seen it
Bengal Tiger - Never seen the pure subspecies
Black Wildebeest - Longleat [2024]
Black-and-White Ruffed Lemur - Too many examples to list
Boa Constrictor - Pretty damn sure I've seen it ... but can never remember where
Bongo - Marwell [2016, 2021, 2022], Berlin Zoo [2022], Paignton Zoo [2024]
Bonobo - Berlin Zoo [2022]
Bornean Orangutan - Paignton Zoo [2017, 2024], Chester Zoo [2019], Jardin des Plantes [2023]
Brazilian Salmon Pink Tarantula - Did the Living Rainforest have these? I think I saw this there
Brazilian Wandering Spider - No idea
Cheetah - Too many examples to list, to my best memory last seen at Whipsnade [2023]
Chinese Pangolin - Never seen it
Collared Peccary - Paignton Zoo [2017, 2024], Marwell [2018, maybe earlier]
Common Death Adder - Probably never seen it
Common Ostrich - Too many examples to list, last seen at Longleat [2024]
Common Warthog - London Zoo [2016, 2021], Berlin Zoo [2022], maybe Marwell at some point
Eastern Brown Snake - Never seen it
Formosan Black Bear - Never seen this subspecies I think, though I have seen the species to which it belongs at Tel-Aviv Safari [2016]
Galapagos Giant Tortoise - Crocodiles of the World [2016?, 2022]
Gemsbok - Berlin Zoo [2022]
Gharial - Berlin Zoo-Aquarium [2022]
Giant Burrowing Cockroach- No idea
Giant Desert Hairy Scorpion - Don't think I have
Giant Forest Scorpion - Don't think I have seen it
Giant Panda - Edinburgh Zoo [2016], Berlin Zoo [2022]
Giant Tiger Land Snail - Don't think I have
Gila Monster - Marwell [2018, after?], Bristol Zoo [2022], Berlin Zoo-Aquarium [2022], Jardin des Plantes [2023]
Golden Poison Frog - Probably have seen it, don't remember where
Goliath Beetle - No idea
Goliath Birdeater - Maybe..?
Goliath Frog - Never seen it
Greater Flamingo - Too many examples to list, last seen at Longleat [2023]
Green Iguana - Don't remember every place I've seen it off the top of my head, but Berlin Zoo-Aquarium [2022] comes to mind
Grizzly Bear - Never seen the subspecies, but I have seen the Eurasian Brown Bear various times over the years
Himalayan Brown Bear - Never seen it
Hippopotamus - Riga Zoo [2015, probably earlier], Tel-Aviv Safari [2016], Berlin Zoo [2022], Whipsnade Zoo [2023]
Indian Elephant - I will be listing the Asiatic Elephant in general here. Tel-Aviv Safari [2016], Jerusalem Biblical Zoo [2016], Chester Zoo [2019], Whipsnade [2021, 2023, probably earlier], Berlin Zoo [2022], Woburn [2023], Longleat [2023]
Indian Peafowl - Too many examples to list, I have even seen feral peafowl
Indian Rhinoceros - Edinburgh Zoo [2016], Chester Zoo [2019], Whipsnade Zoo [2021, 2023], Berlin Zoo [2022]... as much as I can remember
Japanese Macaque - Riga Zoo [2015, maybe earlier], Berlin Zoo [2022]
Komodo Dragon - Tel-Aviv Safari [2016], London Zoo [2021], Crocodiles of the World [2022]
Lehmann's Poison Frog - Never seen it
Lesser Antillean Iguana - Paignton Zoo [2024]
Mandrill - Tel-Aviv Safari [2016], Jerusalem Biblical Zoo [2016], Paignton Zoo [2024]
Mexican Red Knee Tarantula - Too many examples to list
Nile Monitor - Probably never seen it
Nyala - Marwell [2018, 2021, maybe earlier], Berlin Zoo [2022]
Okapi - London Zoo [2016, 2021], Marwell [2018, 2021, 2022, 2023, maybe earlier], Chester Zoo [2019], Berlin Zoo [2022]
Plains Zebra - Too many examples to list, last seen at Longleat [2024]
Pronghorn Antelope - Never seen it
Puff Adder - Probably never seen it
Pygmy Hippopotamus - London Zoo [2016], Marwell [2016, 2017?, 2018, 2020?, 2021, 2022, 2023?, maybe earlier], Edinburgh Zoo [2016], Bristol Zoo [2017, 2018], Berlin Zoo [2022]
Red Deer - Chew Valley Animal Park [2023], Berlin Tierpark [2022], Woburn [2024], Longleat [2024], probably seen it in the wild
Red Panda - Cotswolds Wildlife Park ['over the years', don't remember all] Marwell Zoo [ditto], Bristol Zoo [2017, 2018, 2022], Whipsnade [2021], Berlin Tierpark [2022], probably more other than these
Red-Ruffed Lemur - Marwell [2023]
Reticulated Giraffe - Whipsnade [2023]
Ring-tailed Lemur - Too many examples to list
Sable Antelope - Marwell [2018], Berlin Zoo [2022], Woburn [2024]
Saltwater Crocodile - Paignton Zoo [2017], Crocodiles of the World [2016, 2022]
Siberian Tiger - Marwell Zoo [2016, 2017?, 2018, 2020, 2021, 2022, 2023], Berlin Zoo [2022], Whipsnade Zoo [2021, 2023], Woburn [2024], most definitely others I forgot
Snow Leopard - Marwell [2016, 2017?, 2018?, 2021, 2022, 2023], Welsh Mountain Zoo [2020] Wildkatzenzentrum Felidae [2022], Parc des Felins [2023], most definitely others I forgot
Spotted Hyaena - Wildkatzenzentrum Felidae [2022], Longleat [2024]
Springbok - Never seen it
Thomson's Gazelle - Tel-Aviv Safari [2016]
Timber Wolf - I think Cotswolds Wildlife Park had these at some point or another? If so I've seen it... what I do find funny is how many European zoos have it compared to how few American zoos have it!
Titan Beetle - No idea
West African Lion - Panthera leo leo is still a thing, it's just that it includes the Asiatic Lion too... so it's hardly a 'west African' lion. Thus, too many examples to list.
Western Chimpanzee - Jerusalem Biblical Zoo [2016], Edinburgh Zoo [2016], Welsh Mountain Zoo [2020]... not counting 'other' chimps I have seen
Western Lowland Gorilla - Chessington World of Adventures [2013-ish], Tel-Aviv Safari [2016], Paignton Zoo [2017, 2024], Howletts [2019], Berlin Zoo [2022]
Yellow Anaconda - Tel-Aviv Safari [2016]
~55/80
Arctic Pack
Arctic Wolf - Never seen it
Dall Sheep - Never seen it
Polar Bear - Riga Zoo [2015, probably earlier], Berlin Tierpark [2022]
Reindeer - Beale Park [2016, 2019, 2022, maybe earlier], Berlin Tierpark [2022], Cotswolds Wildlife Park [2023], Whipsnade Zoo [2021, 2023], maybe other places I'm forgetting... not even counting holiday displays
2/4
South America Pack
Capuchin Monkey - I've seen capuchin, but I don't think I've ever seen Cebus capucinus
Giant Anteater - Cotswold Wildlife Park [2015, 2021, maybe earlier], Marwell [2016, 2017, 2018, maybe earlier], Chester Zoo [2019], Zoo Vincennes [2023], Longleat [2024]
Jaguar - Chester Zoo [2019], Berlin Zoo [2022], Zoo Vincennes [2023], Parc des Felins [2023]
Llama - London Zoo [2016, 2021], Chew Valley Animal Park [2023], most probably other farm parks or such elsewhere
Red-eyed Tree Frog - I don't think so somehow
3-4/5
Australia Pack
Dingo - Hamerton [2020... did they have them in 2018?]
Koala - Edinburgh [2016], Longleat [2024]
Red Kangaroo - Riga Zoo [2015].....not sure about anywhere else
Southern Cassowary - Riga Zoo [2015], Birdland [2021, 2024, probably earlier], Cotswolds Wildlife Park [2021, 2023], Berlin Zoo [2022]
Eastern Blue-tongued lizard - Maybe... at Berlin Zoo-Aquarium? [2022]
4-5/5
Aquatic Pack
Cuvier's Dwarf Caiman - Cotswolds Wildlife Park [2021], Crocodiles of the World [2022]
Giant Otter - Chester Zoo [2019], Longleat [2024]
Grey Seal - Riga Zoo [2015, probably before]
King Penguin - Birdland [various years], Edinburgh Zoo [2016]
Diamondback Terrapin - Probably never seen it
4/5
Southeast Asia Animal Pack
Binturong - Edinburgh Zoo [2016], Marwell [after 2018], Cotswolds Wildlife Park [2018-ish], Longleat [2024], Wildkatzenzentrum Felidae [2022], Hamerton [2018, 2020] possibly more I forgot
Clouded Leopard - Cotswolds Wildlife Park [2018, 2024, maybe before], Marwell [2022], Wildkatzenzentrum Felidae [2022], Howletts [2019], possibly more I am forgetting
Dhole - Riga Zoo [2015], Howletts [2019]
Malayan Tapir - Chester Zoo [2019], Jardin des Plantes [2023]
North Sulawesi Babirusa - Chester Zoo [2019], Berlin Zoo [2022]
Proboscic Monkey - Never seen it
Sun Bear - Edinburgh Zoo [2016], Chester Zoo [2019], Berlin Tierpark [2022]
Giant Malaysian Leaf Insect - ...maybe? Not entirely sure
6-7/8
Africa Pack
African Penguin - Whipsnade [2021, 2023], most definitely other places I've forgot
Fennec Fox - Riga Zoo [2015], Tel-Aviv Safari [2016], Berlin Zoo [2022], Longleat [2024]
Meerkat - Far too many examples to list
Southern White Rhinoceros - Cotswolds Wildlife Park [2015, probably before] Marwell [2016, 2017, 2018, 2020, 2021, 2022, 2023, probably before], Whipsnade Zoo [2021, 2023, maybe before], Zoo Vincennes [2018], Woburn [2024], Longleat [2024], maybe others I forgot
Sacred Scarab Beetle - I once saw a scarab of some sort on a hill in the UK ... but I appreciate it was probably not this one
4/5
North America Animal Pack
American Alligator - Tel-Aviv Safari [2016], Crocodiles of the World [2016, 2022], Welsh Mountain Zoo [2020]
Arctic Fox - Chew Valley Animal Park [2023]
Black-tailed Prairie Dog - More examples than I care to list; including Berlin Tierpark [2022]
California Sea Lion - Welsh Mountain Zoo [2020], Woburn [2024], not sure about other places
Cougar - Zoo Vincennes [2023], Parc des Felins [2023]
Moose - The Eurasian subspecies counts, yes? A Latvian reserve sort of thing [2015], Berlin Tierpark [2022]
North American Beaver - Never seen it
American Bullfrog - Never seen it
6/8
Europe Pack
Alpine Ibex - Apparently those at Berlin are Siberian ibex, which are either lumped in with Alpine ibex, or are split as their own species. You choose how you wish to deal with it
Eurasian Lynx - Riga Zoo [2015], Borth Animalarium[!] [2019], Parc des Felins [2023], Whipsnade [2023]... maybe others I'm forgetting
European Badger - Never seen it
European Fallow Deer - Welsh Mountain Zoo [2020], Woburn [2024], probably others I'm forgetting. I have seen it wild a few times
Fire Salamander - Berlin Zoo-Aquarium [2022]
3-4/5
Wetlands Animal Pack
Asian Small-Clawed Otter - more examples than I care to list.
Capybara - Riga Zoo [2015], Cotswolds Wildlife Park [2018?, 2021, 2023, probably others I forget], Marwell [at some point?], Beale Park [2022], Berlin Zoo [2022], Chew Valley Animal Park [2023], probably others
Nile Lechwe - Edinburgh Zoo [2016]
Platypus - never seen it
Red-crowned Crane - Whipsnade Zoo [2021], Berlin Tierpark [2022], probably Hamerton at some point
Spectacled Caiman - Crocodiles of the World [2016, 2022], possible Chester too
Wild Water Buffalo - I've seen the domestic form at Berlin Zoo [2022], not sure if that counts
Danube Crested Newt - probably haven't seen it
5-6/8
Conservation Pack
Amur Leopard - Marwell [2016, 2018, 2020]... somehow nowhere else comes to mind though I'm sure I've seen it elsewhere
Axolotl - London Zoo [2016], Edinburgh Zoo [2016], Jardin des Plantes [2023], possibly Birdland at one point or another
Przewalski's Horse - Riga Zoo [2015], Welsh Mountain Zoo [2020], Berlin Tierpark [2022], Jardin des Plantes [2023], Marwell [various years, last in 2023], Whipsnade [2023, maybe before], possibly others
Scimitar-horned Oryx - Marwell [various years], Berlin Zoo [2022], Woburn [2024], Longleat [2024]
Siamang - Marwell [various years], Cotswolds Wildlife Park [various years]... probably others
5/5 [full house!]
Twilight Pack
Common Wombat - Hamerton [2018]
Egyptian Fruit Bat - Cotswolds Wildlife Park [various years], probably elsewhere
Raccoon - Zoo de Labenne [2015, maybe before], Millets Falconry [2022, maybe 2017], Hamerton Zoo [2018, 2020], Chew Valley Animal Park [2023], possibly others
Red Fox - Said Latvian reserve [2015], Chew Valley Animal Park [2023]
Striped Skunk - Crocodiles of the World [2016], Cedars Nature Centre [2018], Beale Park [2019], Chew Valley Animal Park [2023]
5/5 [full house!]
Grasslands Animal Pack
Blue Wildebeest - Tel-Aviv Safari [2016], Woburn [2024]
Caracal - Wildkatzenzentrum Felidae [2022]
Cloudless Sulphur - nope
Emu - More examples than I care to list
European Peacock Butterfly - probably in the wild at some point
Maned Wolf - Berlin Tierpark [2022]
Menelaus Blue Morpho - don't think so
Monarch Butterfly - don't think so
Nine-banded Armadillo - never seen it
Old World Swallowtail - don't think so
Red-Necked Wallaby - more examples than I care to list
Striped Hyaena - Wildkatzenzentrum Felidae [2022]
7/12 [including butterflies], 6/7 [excluding butterflies]
Tropical Pack
Asian Water Monitor - Crocodiles of the World [2016, 2022], probably elsewhere
Brown-throated Sloth - never seen it
Fossa - Marwell [2017, likely before], Wildkatzenzentrum Felidae [2022]
Lar Gibbon - Tel-Aviv Safari [2016], Hamerton Zoo [2018, 2020?], Welsh Mountain Zoo [2020], most definitely others
Red River Hog - Edinburgh Zoo [2016], Paignton Zoo [2017], Chester [2019], Howletts [2019], London [2021], Marwell [2021, 2022, 2023], Jardin des Plantes [2023]
4/5
Arid Animal Pack
Addax - Marwell [various years], Zoo Vincennes [2023], maybe others
African Crested Porcupine - more examples than I care to list
Black Rhinoceros - Paignton Zoo [2017, 2024], Howletts [2019]
Dama Gazelle - Not entirely sure of the subspecies but I have seen the species it belongs to in Berlin Tierpark [2022] and Zoo Vincennes [2023]
Desert Horned Viper - don't think so
Dromedary - Zoo de Labenne [2015, probably earlier]
Sand Cat - Bristol Zoo [2017], Parc des Felins [2023]
Somali Wild Ass - Marwell [2020?, 2021, 2022, 2023]
7/8
Oceania Pack
Little Penguin - Never seen it
North Island Brown Kiwi - Berlin Zoo [2022], Paignton Zoo [2024]
Quokka - Never seen it
Spectacled Flying Fox - Never seen it
Tasmanian Devil - Jardin des Plantes [2023]
2/5
Eurasia Animal Pack
Hermann's Tortoise - Zoo Vincennes [2023]
Mute Swan - Numerous times in the wild... but never in a zoo
Saiga - Never seen it
Sloth Bear - Berlin Zoo [2022]
Sichuan Takin - Berlin Zoo [2022], Zoo Vincennes [2023]
Wisent - Howletts [2019], Whipsnade [2021, 2023], Berlin Zoo [2022]
Wolverine - Cotswolds Wildlife Park [2018, 2023, probably earlier], Whipsnade Zoo [2023]
7/8
Barnyard Animal Pack [I have seen all of these at the species level... will do breed-level here]
Alpaca - More examples than I care to list
Alpine Goat - Probably not
American Standard Donkey - I think at Hamerton [2018 or 2020]
Highland Cattle - Most recently at Beale Park [2022]
Hill Radnor Sheep - Willing to say I have ... been to Wales, seen sheep
Sussex Chicken - Probably seen it
Tamworth Pig - Seen it at the Knepp Estate [2023]
6/7
Zookeper's Animal Pack
African Spurred Tortoise - Crocodiles of the World [2016], most probably others
Coquerel's Sifaka - Cotswolds Wildlife Park [various years]
Hamadryas Baboon - Paignton Zoo [2017], Berlin Zoo [2022]
Kirk's Dik-dik - Cotswolds Wildlife Park [2023], Jardin des Plantes [2022], Marwell [2023], Longleat [2024]
Markhor - Berlin Tierpark [2022], Jardin des Plantes [2023]
Pallas' Cat - Cotswolds Wildlife Park [various years], Berlin Tierpark [2022]
Spectacled Bear - Chester Zoo [2019]
7/7 [full house!]
In total:
140-150/195
~75% of the entire roster