When he was a child, Baelfire was attacked and bitten by an Atlantean Rat Snake. Milah killed the creature, before asking the help of Fendrake the Healer to cure their dying son. Eventually, thanks to a potion, Baelfire is saved. ("Devil's Due")
Agrabahn Vipers are an Agrabah species. They first appear in the eleventh episode of the first season. They are two-headed snake creatures who are well known for their ability to kill with a single bite. Their venom can be extracted, and drinking it is lethal.
Ursula, a mermaid named after the Sea Goddess and the daughter of Poseidon. After the loss of her singing voice, Ursula decides to become strong and powerful like her namesake, and she uses her father's trident to transform herself into a cecaelia. ("Poor Unfortunate Soul")
Chimeras are an Enchanted Forest species. They are first mentioned in the sixth episode of the one season. They are described as a combination of a lion, a serpent, and a goat. They can be cooked, and their taste is said to be similar to that of turducken.
Hercules is the son of Zeus and a mortal woman. He has the power of super strength.
Dwarves are an Enchanted Forest species. They first appear in the fourteenth episode of the first season. They are humanoid creatures and shorter than humans who hatch from eggs (in their adult size), and their only gender is male. There are no female dwarves in existence. They are naturally hard-working, most of them are miners.
Gnomes are an Enchanted Forest species. They appear in the second episode of the first season. They are little short humanoid creatures, with greenish skin and pointed ears. Not much is known about them, but they seem to take pleasure in mocking others, especially when they fail at something.
A gnome, which was one of the land's inhabitants with the darkest souls, helped the Evil Queen at her first attempt to enact the Dark Curse, by giving up a lock of his hair. When the gnome laughed at her failure, the Queen turned him to stone.
Krakens are an Enchanted Forest species. The Kraken is a monstrous giant squid. Their blood can be harvested to be used for the Nautilus component that would enable it to travel to any oceans of the worlds.
After Captain Hook joins Captain Nemo and Liam on a treasure hunt, a giant squid grabs onto him with its tentacles, but before he is dragged underwater, Nemo and Liam are able to free him from the creature. ("Dark Waters")
Monstro is an Enchanted Forest creature. It appears in the twentieth episode of the first season. Monstro is a giant whale at sea who attacks and attempts to swallow Geppetto and Pinocchio while they are caught in a storm. Pinocchio sacrifices himself to give Geppetto the last life vest and jumps into the sea as a huge tidal wave engulfs everything.
Werewolves are an Enchanted Forest species. They first appear in the first episode of the first season. A person has the ability to turn into a wolf if born via genetic inheritance with the ability to shapeshift during the full moon, also known as "wolf's time". A person born without the gene can become susceptible to also having the ability to shapeshift by being scratched by a werewolf.
Merida and Emma tracked down a wisp when they met. After Merida captured it, she told Emma that she would be able to use it after her. However, after being convinced by the Darkness - under Rumplestiltskin's appearance - that Merida was lying, Emma confronted the warrior queen, as she was asking the Wisp to help her. After their confrontation, the wisp "runs away", and Merida decides to go after it. ("The Dark Swan")
Flying Monkeys are an Oz species. They first appear in the twelfth episode of the third season on Once Upon a Time. They are humanoid creatures with fur-covered bodies that resemble primates. They have a pair of wings that allow them to fly. After Zelena's powers are taken away by Regina, everyone she once turned into a flying monkey reverts to their human forms.
A fury appeared at Storybrooke, kidnapping Robin Hood. After she discovered the identity of the creature, Regina understood that she was paying the price of something which happened in Camelot. As the fury was taking Robin's life out of him, Regina decided to sacrifice herself, so the fury chose to take her life. However, Mary Margaret, David, Leroy and King Arthur chose to stand by Regina, forming a human chain while the fury was still absorbing Regina's life. The creature was unable to take all the lives at the same time, and it exploded. ("The Price")
Dodos are a Wonderland species. They are first mentioned in the second episode of the spin-off series, and they appear in the graphic novel, Out of the Past. Dodos are large, talking bird-like creatures, with grey feathers and orange feet. Their big hooked bill was a red color. They have two short wings, with hands at the top of them.
Dragonflies are a Wonderland species. They appear in the first episode of the spin-off. Dragonflies are insects about the size of a medium bird. Each one has a pair of translucent wings and a long tail with several short leg appendages, a pointed mouth, as well as two distinct horns sticking out the crown of their heads. They have the ability to breathe out large mouthfuls of fire.
A dragonfly lingering overhead at the Mallow Marsh is grabbed by Alice, who uses it to spray fire onto the sticky surface of the swamp, and frees herself and Knave from sinking in deeper. ("Down the Rabbit Hole")
There are many other dragonflies flying around the area of the Mallow Marsh. ("Down the Rabbit Hole")
Five Mome Raths attacked the Red Queen, Alice, and Cyrus when they were tied to a post by peasants are angry at the Red Queen for not protecting their lands from the wild beasts that have been invading their lands. The lit fires surrounding the trio attract them, even though they put out the torches, due to the glow of Alice's necklace. She throws the pendant at the Mome Raths, who then begin fighting over the object, while the three of them flee. ("Nothing to Fear")
The Sarlacc is a Wonderland creature. It is mentioned in the third episode. In the Red Queen's book, it is depicted as a long quadruped creature with two tusks and a tail. The book also shows it as living on a mountain near the ocean. It is able to digest his victims over a millennia.
Wonderland Rabbits are a Wonderland species. They first appear in the first episode of the spin-off. These anthropomorphic creatures have the ability to speak, to walk on two legs, and to think and act like human people. They are also wearing clothes.
Known Wonderland Rabbits:
Mrs. Rabbit is a healer. As the wife of the White Rabbit, she was kidnapped with her children by the Red Queen to force her husband to betray Alice. Eventually, she is freed while her husband decides to help Alice against her enemies.
Mrs. Rabbit's mother and grandmother are also healers. They taught her how to become as good as they were. Mrs. Rabbit's mother is still alive, but it is unknown if her grandmother is.
Percy, better known as the White Rabbit, is a close friend of Alice. Having the ability to open portals to other worlds, he is forced to take part in conflicts which are dangerous to him and his family.
The White Rabbit's Daughter is kidnapped with her mother and her brother, when the Red Queen forced the White Rabbit to help her against Alice. Eventually, she is freed with the rest of her family.
The White Rabbit's Son was kidnapped with his mother and his sister when the Red Queen forced the White Rabbit to help her against Alice. Eventually, he is freed with the rest of his family.
Species of Different Origins
Bandersnatches are Wonderland and New Wonderland species. They first appear in the third episode of the spin-off. They are large and extremely fast four-legged creatures bearing a resemblance to wild boars. A pair usually mates for life and when one dies, the other follows in death.
As a child, Alice ventures into Wonderland and is left terrified by an encounter with a Bandersnatch. At an older age, she returns and Cyrus teaches her an advantage over Bandersnatches as they have very poor eyesight. ("Forget Me Not")
A Bandersnatch is released by the Red Queen and Jafar to attack Alice so she is forced to make her first wish. Alice tricks the beast with the forget me knot with an illusion of herself and Knave, to which the Bandersnatch leaps right into. At this, Alice pulls the forget me knot's rope to loop and hold the Bandersnatch in place. Later, Knave bursts in to kill the creature with a knife. ("Forget Me Not")
When Knave kills the Bandersnatch, the animal's mate also dies shortly after. ("Forget Me Not")
Deities are Enchanted Forest and Mount Olympus species. They first appear in the sixth episode of the third season. Also known as Gods, they are mythical and powerful beings whose existence is uncertain for a lot of people. They are known to be immortal and to have huge powers.
Fairies are an Enchanted Forest, Wonderland, Wish Realm and New Enchanted Forest species. They first appear in the first episode of the first season. They are humanoid little creatures with insect-like wings. Each fairy has a colorful light surrounding their tiny bodies, with their dresses, hair decorations, and wings being the same color. They use fairy dust to practice their magic. Thus far, only female fairies are known to exist. They are able to take on a human size, but this form is wingless. They are good by nature (with one exception) which led them to become nuns during the curse.
The Blue Fairy, also known as the Reul Ghorm, the Scottish word for "the Blue Star", is a very powerful fairy. She often comes to the aide of those who wishes upon a blue star and can grant wishes. ("The Return")
Nova, a pink, rookie and clumsy fairy that wishes to become a fairy godmother one day. She falls in love with Dreamy, a dwarf, but she does not leave to start a future with him as planned since the Blue Fairy warns she will lose her wings if she does. ("Dreamy")
Tinker Bell, a fairy who ends up losing her wings after disobeying the Blue Fairy in an attempt to help Regina find true love. Currently, she retains none of her former fairy powers. ("Quite a Common Fairy")
A mermaid, originally part of a swarm ramming Hook's ship, is separated after being caught on fishing line by Emma and Mary Margaret. Along with her, a conch shell stuck in the net is pulled up to deck. Unable to plead her way through to being set free, the mermaid signals a sound from the shell to the sky; causing a rumbling of an approaching storm. She warns they must let her go, or die. Unable to come to a unanimous decision with the others, Regina makes the choice to turn the mermaid into a wooden statue to stop whatever was summoned by the shell. Rather than that, it speeds up into a full-on storm. ("The Heart of the Truest Believer")
Numerous other mermaids swim through Neverland's surrounding ocean. ("The Heart of the Truest Believer")
The Nemean Lion is a creature of unknown origin. It is mentioned in the thirteenth episode of the fifth season. The Nemean Lion was a powerful creature with fur as impenetrable as steel, making it invincible. Hercules' first labor was to defeat the beast. After a long exhausting fight against the Lion, Hercules accidentally dropped his torch which sets a brush on fire. The flames siged the Lion's fur from his body, so it lost its invincibility. Then, Hercules slew the beast, completing his first labor.
Pixies is a creature of unknown origin. They are mentioned in the eighteenth episode of the third season. Little is known about this species, but they are known to be small in size, as Cora remarks that Jonathan "must have the brain the size of a Pixie". Pixie Dust takes its name from them.
Sea Nymphs are a species of unknown origin. They are mentioned in the graphic fiction novel, Out of the Past. Not much is known about them. They live in a different realm than the Enchanted Forest. They have magic sand, which neutralizes any magic.
Known Sea Nymphs:
A Sea Nymph meets and gives some magic sand to William. He uses it against the Evil Queen, before being killed.
The Wraith is a creature of unknown origin. It first appears in the first appear of the second season. It hunts its victim down and sucks its soul out, leaving a lifeless body. According to Regina Mills, it is an undead creature and thus cannot be killed again. A Wraith Amulet is able to summon it.