Is Fantastic Beasts and Where to Find Them an exhaustive list of magical animals in the Harry Potter world?

Question

Fantastic Beasts and Where to Find Them is a pseudo in-universe book describing magical animals from the Harry Potter world.

Is it an exhaustive list though? Do other creatures exist that don't feature in the book?

I'm asking because of this comment, by Gabe Willard:

No creatures matching her description are listed in Fantastic Beasts and Where to Find Them. If you can, make an answer. I'm fairly confident she's a Muggle snake, however. Such an absence from FBWFT would be unexpected.

Emphasis mine.

Is such an absence unexpected? Are other 'well known' creatures that aren't featured in that book?

Answer 1

I do think it's particularly telling that Nagini -- the kind of snake she is -- is missing from Fantastic Beasts and Where to Find Them. There are magical snakes listed in FBAWTFT, such as the Ashwinder and the Runespoor. I agree with Gabe in that Nagini is a Muggle snake -- a Naga snake, to be specific (a snake which has mythical properties according to Hindu legend, and most resembles a giant cobra). I find it interesting, though, that Voldemort would choose a Muggle snake for himself. That seems telling in some way, although how I'm not sure.

Anyway, there are creatures missing from FBAWTFT that are mentioned in the novels:

• Hinkypunks
• Blast-ended Skrewts (Hagrid somehow invented these creatures, but one was included in the third task of the Triwizard Tournament, which gives it legitimacy).
• Animagus (this one is iffy, but if a werewolf is listed, I think an Animagus might be worth a mention. However, Animagi turn into Muggle animals, not magical creatures, so it's quite likely this wouldn't apply. Because, really. Being a unicorn Animagus would be so Mary Sue).
• Blood-Sucking Bugbears
• House-elves
• Double-ended newts
• Boggarts
• Owls (Owls in Potterverse have some unique qualities, such as being able to find anyone anywhere and the ability to not be tracked. They also want payment for their services. They're just different than Muggle owls)
• Ghosts, spirits, and poltergeists
• Veela
• Hags
• Giants
• Goblins
• Dementors
• Nargles¹
• Crumple-Horned Snorkack¹
• Unknown Creatures in the Lestranges' vault at Gringotts: [T]he door of the vault melted away to reveal a cave-like opening crammed from floor to ceiling with golden coins and goblets, silver armour, the skins of strange creatures, some with long spines, others with drooping wings[.] (These could obviously be skins of already known creatures which are simply not identified as such)

¹Kidding, kidding ...

Answer 2

Yes, it's likely that not all the magical creatures known to the wizarding world were included in this textbook.

A list of magical creatures included in the book: http://harrypotter.wikia.com/wiki/Fantastic_Beasts_and_Where_to_Find_Them

Off the top of my head, Basilisks, Boggarts, and Thestrals are not explicitly included on that list. Considering that this was meant as a textbook for the classroom, I would assume that only relatively common creatures of the wizarding world would've been included as an introduction to the topic of magical beasts and where to find them.

As a side note, remember that Voldemort was a parselmouth. Nagini wouldn't have to be a magical snake for Voldemort to communicate with the snake and get it to do his bidding.

Answer 3

Some creatures were left out at the request of the President of MACUSA

At President Picquery’s request, I made no mention of the more important American magical creatures in the first edition of Fantastic Beasts, because she wished to deter wizarding sightseers. As the American wizarding community was subject to greater persecution at that time than their European counterparts, and given that I had inadvertently contributed to a serious breach of the International Statute of Secrecy in New York, I agreed.
_{Fantastic Beast and Where to Find Them (2017 textbook) - Foreword by the Author}