Below are my list's for the quest's, please feel free to help yourselves, for the level critter's I have broken them up into their own categories, for instance if you start of with fox and raccoon then next mth you will have hedgehog and hare, the same goes for intermediate and advanced, the birds list is the chick's, which are in alphabetical order, so if you have the crane this mth you should have the jackdaw next mth, any questions just ask, some will also notice a jump in some of their level critter's, this is because of where we first started out, below is a list of critter's I know of so far that have jumps.
some extra info although am sure most have figured out, the rainforest critter's just run one after each other every mth, as in okapi, tree frog etc, candies in extreme also run one after the other every mth, the bday critters in advanced also run one after the other from the guide, except for the bday dodo, bday trex, bday orangutan and bday albino raccoon which are only in extreme, the field mouse and duck alternates every mth for easy, as does the myths wd, rd and gd, and in intermediate, it's griff through to unicorn and back again, chicks in advanced are in alpha

Melanistic, Albino, Topiary, Cake...Intermediate

Birthday Dodo, Birthday T-Rex, Birthday Orangutan, Birthday Albino Racoon...Extreme

Extreme----Albino Kiwi, Albino Badger, Golden Hen and The Loch Ness Monster

Easy
fox, hedgehog, mole, brown bunny, grey squirrel, wren, wagtail, chaffy, cuckoo, raccoon, hare, singing bush lark, skunk, gecko, camel, donkey, deer and magpie

Intermediate
Tortoise, Lop bunny, meerkat, road runner, armadillo, piglet, ostrich, chipmunk, coyote, wolf, bee eater, guinea pig, giraffe, woodpecker, barn owl, zebra, crane, toad, blue jay, seal, king penguin, puffin, walrus, platypus, otter, sea lion, Llama, chickadee, prairie dog, Aardvark, gazelle, leopard, oriole, bandicoot, sugar glider, Hippo, roo and wallaby

Advanced
red squirrel, waxwing, kiwi, porcupine, fairy pink armadillo, badger, Olinguito, nightingale, elephant, Long eared owl, Australian king parrot, pair of magpies, jackdaw, king fisher, ferret, rockoon, froog, snabbit and ping-pong, giant ant eater, tiger, wombat,  koala, taz, giant panda, red panda and gorilla

Advance
Bday Wriggly, Bday Maid, Bday Elephant, Bday Tortoise, Bday Froog, Bday Fox, Bday Baby Uni, Bday Toad, Bday Badger, Bday Uni, Bday Kinkajou, Bday Wise Fairy.

Chicks for Advanced.
Bee Eater, Blue Jay, Chaffinch, Chickadee, Crane, Jackdaw, Kingfisher, Magpie, Nightingale, Oriole, Roadrunner, Singing Bush Lark, Waxwing, Woody, Wren and Yellow Wagtail

Jumps I know of so far and important to remember.
Toad to tortoise
Gorilla to kingfisher
Jackdaw to Red Squirrel
Bee Eater to Aardvark
Prairie Dog to Gazelle
Magpie to raccoon
Wallaby to blue jay
Cuckoo to Fox
Aardvark to Guinea pig (thanks Susan)

As we have all started the quest's at different points for the wildlife critter's, some will have jumps, the above are all the jumps.
UPDATED

Thanks for spotting

I found this helpful:

for attracting underwater frogs
-------------------------------------
step 1

check your TADPOLES number if it is the same with FROGLET number.. IF tadpoles number is bigger you have more froglets available to visit your garden

step 2 sum ADULT UW FROGS number        (XXX)
                  SPOOOKY UW FROGS number    (XXX)
                                                             --------------
          =        TOTAL FROGS                        (XXX)                             

step 3      FROGLETS (XXX)   -   TOTAL FROGS (XXX)  = the number of frogs you have available to come in your garden

ex   80 froglets - 71 total frogs = 9 available frogs to come

-----------------------------
for attracting land frogs
-----------------------------
step 1

check what you have spotted in other gardens

ADULT UW FROGS number  (XXX) AND SPOOKY FROGS number (XXX) = TOTAL FROGS SPOTTED

step 2

see how many sets are availabe

TADPOLES number       (xxx)
FROGLETS number       (xxx)
TOTAL FROGS number  (xxx)