On wizardingworld.com (formerly known as Pottermore), there are 140 possible patronus forms you can conjure if you take their patronus quiz. One of these may be yours! That being said, there are some missing which probably should be included. I've listed those here as well. Not every possible patronus form has been added to this list, however, because that would be impossible!
Images of each of Wizarding World's Patronus Forms can be found at:
https://harrypotter.fandom.com/wiki/Patronus_Charm
1. Dolphin
2. Tonkinese Cat
3. Manx Cat
4. Nebelung Cat
5. Fox
6. St Bernard Dog
7. Weasel
8. Bassett Hound
9. Black And White Cat
10. Hedgehog
11. Deerhound
12. West Highland Terrier
13. Siberian Cat
14. Tortoiseshell Cat
15. White Stallion
16. White Mare
17. White Swan
18. Osprey
19. Borzoi
20. Ragdoll Cat
Bat
Black Bear
Brown Owl
Buffalo
Cheetah
Doe
Eagle Owl
Elephant
Great Grey Owl
Hyena
Impala
King Cobra
Leopard
Leopardess
Lion
Lioness
Little Owl
Lynx
Orca
Oryx
Peacock
Polar Bear
Python
Raven
Rhinoceros
Scops Owl
Seal Shark
Snowy Owl
Stag
Tiger
Tigress
Vulture
Abraxan Winged Horse
Dragon
Erumpent
Fire-dwelling Salamander
Granian Winged Horse
Hippogryff
Occamy
Runespoor
Thestral
Unicorn
Black Swan
Dolphin
Heron
Orca
Salmon
Seal
Shark
White Swan
Not included on Wizarding World:
Albatross
Alligator
Crab
Crocodile
Duck
Frog
Goose
Penguin
Scorpion
Turtle
Black Bear
Brown Bear
Polar Bear
Not included on Wizarding World:
Panda Bear
Blackbird
Buzzard
Crow
Eagle
Falcon
Goshawk
Hawk
Hummingbird
Kingfisher
Macaw
Magpie
Marsh Harrier
Nightjar
Osprey
Ostrich
Peacock
Pheasant
Pine Marten
Raven
Robin
Rooster
Sparrow
Sparrowhawk
Swallow
Swift
Vulture
Not included on Wizarding World:
Bluebird
Bluejay
Dove
Hawk
Rooster
Cheetah
Impala
Leopard
Leopardess
Lion
Lioness
Lynx
Tiger
Tigress
Wildcat
1. Doe
2. Stag
Basset Hound
Beagle
Bloodhound
Borzoi
Chow Dow
Deerhound
Fox
Fox Terrier
Greyhound
Husky
Ibizan Hound
Irish Wolfhound
Mastiff Dog
Mongrel Dog
Newfoundland
Rottweiler
St. Bernard
West Highland Terrier
Wolf
Not included on Wizarding World:
too many to list.......
Black and White Cat
Calico Cat
Ginger Cat
Manx Cat
Nebelung Cat
Ocicat
Ragdoll Cat
Russian Blue Cat
Siberian Cat
Sphynx Cat
Tonkinese Cat
Tortoiseshell Cat
Not included on Wizarding World:
Persian Cat
Tabby Cat
Bay Mare
Bay Stallion
Black Mare
Black Stallion
Chestnut Mare
Chestnut Stallion
Dapple Grey Mare
Dapple Grey Stallion
Dun Mare
Dun Stallion
Piebald Mare
Piebald Stallion
White Mare
White Stallion
Not included on Wizarding World:
Mustang
Abraxan Winged Horse
Dragon
Erumpent
Fire-dwelling Salamander
Granian Winged Horse
Hippogryff
Occamy
Runespoor
Thestral
Unicorn
Not included on Wizarding World:
Griffin
Phoenix
Capuchin Monkey
Orangutan
Not included on Wizarding World:
Ape
Gorilla
Monkey
Brown Owl
Great Grey Owl
Eagle Owl
Little Owl
Scops Owl
Snowy Owl
Not included on Wizarding World:
Barn Owl
Screech Owl
Brown Hare
Mountain Hare
Not included on Wizarding World:
Hare
Jackrabbit
Rabbit
Field Mouse
Grey Squirrel
Red Squirrel
Vole
Woodmouse
Not included on Wizarding World:
Beaver
Chinchilla
Chipmunk
Guinea Pig
Rat
Adder
Black Mamba
Grass Snake
King Cobra
Python
Rattlesnake
Not listed on Wizarding World:
too many to list........
Badger
Mink
Otter
Polecat
Stoat
Weasel
Not listed on Wizarding World:
Ermine
Ferret
Mink
River Otter
Sea Otter
Wolverine
Aardvark
Bat
Buffalo
Dragonfly
Hedgehog
Mole
Rhinoceros
Shrew
Wild Boar
Butterfly
Camel
Coyote
Giraffe
Goat
Kangaroo
Porcupine
Ram
Sheep
Spider
Wombat
Zebra
Sources:
https://www.wizardingworld.com/features/what-your-patronus-says-about-you