As the name of the franchise suggests, Fantastic Beasts features many magical and fantastical creatures. Some of these first appeared in the original Harry Potter series, but many of them are new to the franchise.
The Fantastic Beasts series properly introduced fans to the mischievous Nifflers, the adorable Bowtruckles and the all-seeing Demiguise. Many of these critters will likely appear in the third movie along with new ones too. Lead character Newt Scamander has created a whole world of different landscapes for these wonderous creatures, all within the confines of his suitcase.
Doxies
Doxies are often referred to as "biting fairies" but are actually a different species. Like fairies, Doxies are small and have wings, but they also have sharp teeth, extra arms and legs, and large ears.
Doxies are notorious for biting, and their venom is known to be poisonous. Although Doxies are one of the creatures the Harry Potter movies didn't show, they are shown briefly in Newt's case. Their appearance may be minor, but their peculiar and menacing appearance means they are quite eye-catching. It would be great if these pests showed up again in the franchise and for fans to see how they compare to the mischievous Cornish Pixies from the original series.
Fwooper
Fwoopers are brightly colored birds, and while they look like fairly innocent creatures, they can be deadly. The birds' feathers are said to be brightly colored because they originated from Africa.
The song of a Fwooper is enough to drive a person mad, so only one should be owned at any given time. Wizards who keep one of these birds are advised to put a silencing spell on the Fwooper to ensure the wizard retains their sanity. Newt has a bright-purple Fwooper inside his case, so fans will be hoping he's put a silencing charm on his feathered pet.
Swooping Evil
The Swooping Evil hides itself in a small cocoon, but when it reveals itself, its quite intimidating to behold. The creature has bright blue wings like a butterfly but has a wolf-likeskull in place of a head.
This creature is particularly dangerous because it eats human brains, something it's seen trying to do in the first Fantastic Beasts movie. The Swooping Evil plays an important role in Newt and Tina's escape from MACUSA, so it wouldn't be too surprising if Newt uses The Swooping Evil again in order to get himself out of a tight situation.
Grindylow
Grindylow are small water-demons and have featured in both of the Fantastic Beasts movies so far. Grindylow use their tentacles to navigate through their underwater habitat and are known to be aggressive in nature.
One of the most magical scenes from Goblet of Fire depicts the second task of the Triwizard Tournament in which Harry is attacked by Grindylow while trying to save Ron and the others from the Merpeople. The water-demons show their aggressive nature here as they try to stop Harry leaving The Black Lake. As these creatures appear in the Harry Potter series, it was exciting for fans to see them floating around in water bubbles in Newt's case and to witness him caring for them in flashbacks to his time at Hogwarts.
Frank The Thunderbird
The aptly named Thunderbird is a huge avian creature that can summon storms. From Arizona, The Thunderbird is a regal creature that is highly sensitive to danger. In the first Fantastic Beasts movie, Newt has a Thunderbird named Frank in his case.
Frank proved pivotal to the resolution of this movie as he created a rainstorm (laced with Swooping Evil venom) in order to obliviate the population of New York. Frank eventually flies off to return to Arizona so is no longer living within Newt's case, but this creature's magnificence and importance to the plot can't be denied.
Zouwu
The Zouwu is a gigantic feline creature, and, despite its intimidating size, Newt successfully tames it using a small toy. The Zouwu in the second Fantastic Beasts movie was kept in captivity as part of Skender's circus, but was later recused by Newt.
One of the traits that Newt and Harry Potter share is their rapport with animals (including dangerous ones like the Zouwu). Newt uses a small toy in order to tame the Zouwu and lure it into his case, which it now calls home. Due to its apparent ability to apparate, it would be interesting to see how Newt keeps the Zouwu under control and stops it from causing havoc within the case.
Nifflers
Nifflers are small and adorable platypus-like creatures who cause havoc in the Fantastic Beasts series. In a memorable scene from the first movie, Newt has to chase an escaped Niffler through a bank, which is where he first encounters Jacob.
Newt has several Nifflers within his case, but they're often escaping and causing trouble. These creatures have an attraction to anything shiny, which means they can be quite a menace, but they did prove useful after one of them stole The Blood Pact from Grindelwald. The Nifflers are extremely adorable and have become firm fan favorites.
Bowtruckles
The tiny, hand-sized Bowtruckles dwell within trees and, due to to their stick-like appearance, can camouflage into their environment. These creatures are also expert lock-pickers, which makes them useful pets to have.
While Newt has many Bowtruckles within his case, he has a special bond with one in particular: Pickett. This Bowtruckle seems to have some attachment issues and loves to travel around with Newt in his top pocket. Pickett was especially displeased when Newt almost gave him away, showing the mischievous nature of a Bowtruckle by blowing raspberries at his owner.
Dougal The Demiguise
Demiguise resemble a cross between a sloth and a monkey and have long silver hair. Dougal is a Demiguise who lives within Newt's case. He is shown to be particularly protective, caring for a young Occamy after they both escape from the case.
There are several overt connections between Harry Potter and Fantastic Beasts but a more subtle and less obvious one stems from The Invisibility Cloak. Demiguise fur can be used to weave invisibility cloaks because these creature possess the ability to turn invisible. They also have the ability to see the future. Both abilities make them difficult to catch. Due to these special powers and because he is so caring and endearing, Dougal is one of the most loveable beasts in Newt's case.
Occamies
Occamies are winged, serpentine creatures that hatch from eggs of pure silver. These fantastic animals can grow and shrink in size in order to fill available spaces, which is seen during an exciting sequence in the first Fantastic Beasts movie. An Occamy made itself at home in an department store under the watch of Dougal before being captured in a teapot.
Since Occamies are able to change, Newt could certainly make use of them in future movies. Occamies are beautiful creatures, and their unusual abilities make them easily some of the most intriguing in Newt's suitcase.