Baby dragons hatch from eggs, which is the beginning of the second stage of a dragon's life cycle. This stage is known as the Tiny Tooth. See more of the first stage of a dragon's life cycle at the page Dragon Eggs.
Baby dragons are small in size. Some are playful, mischievous and appear adorable to even the toughest of Vikings, as shown when Stoick commented that baby Thunderdrums were cute. Others, however, are aggressive. Newly hatched Whispering Deaths have mouths full of sharp teeth and are unable to control their teeth and spines, thus making them dangerous. All baby dragons have the ability to withstand a Bewilderbeast's mind control as they "listen to no one."
Born from an egg with spikes; baby Nadders come in a assortment of tropical colors, like their parents. Like most baby dragons, their teeth, horns, spines, talons, and claws are smooth and not sharp. They also have some of the most alert senses, most spryness, and are able to fly sooner the other baby dragons. They tend to flock around their mothers for protection and food (mostly regurgitated fish). They will only strike out on their own during maturity in the broad wing stage.
A baby Nightmare can set itself on fire as soon as they hatch. They are born from an egg that's on fire. Baby Nightmares are some of the most willful baby dragons, and are known for being the first to separate from their litter and assume independence within minutes of their birth. Their saliva, due to it's kerosene composition, is akin to lighter fluid, which indirectly gave Hiccup the idea for Inferno, his flame sword. Despite their self-reliance and solitary natures, Nightmares grow up to be some of the most devoted dragons and are particularly protective of their Viking riders, even if they have a funny way of showing it sometimes.
Baby Gronckles, like their parents, are lousy fliers, crash landing, falling, and bumping into things, and they are the only known baby dragon to sleep most of the time.
Hatched from a double egg, baby Zipplebacks are really playful and curious. As a baby, one head can breathe gas, but the other can't light it with sparks until it matures. Sometimes double the babies can equal quadruple the headaches! Such is the case with Zipplebacks, whose two heads want different things at the same time!
Baby Zipplebacks benefit from having a close relationship with their siblings, from increased hunting (one head watches while the other makes sure the coast is clear) to higher levels of problem solving abilities(one head scares pray into the waiting jaws of the other.)
Whispering Death babies are the only known dragons to be born with razor sharp teeth, spines, and uncontrollable jaw strength.
Baby Thunderdrums can be very loud and uncontrollable unless corralled by a bigger, older Thunderdrum, such as how Thornado could control Bing, Bam, and Boom. A baby Thunderdrum's playful nature can lead to destruction, noise making, and making a mess where ever they go. Once you get past the loudness and the destruction, baby Thunderdrums are pretty cute. But in order to see them clearly, they have to be still, which is hard because baby Thunderdrums are always on the move. Like adults, babies can be heard from miles away, which is helpful when a baby calls for its mom.
Baby Thunderdrums are considerably larger than other baby dragons.
Typhoomerangs are born with sharp talons and razor sharp claws, and although other baby dragons are the size of house cats, the baby Typhoomerang is the size of a young yak.
So far, only baby Scuttleclaws have been seen in the movies. As infants, they're playful and listen to no one. Not even a Bewilderbeast can put them under command. And this trait could be, rather eccentrically, one of few countermeasures to effectively the kings' dragon controlling. They also enjoy playing with Toothless, though the feeling isn't mutual. Scuttleclaws often scatter if roared at by larger dragons. It resembles a cross between a Deadly Nadder and a Hideous Zippleback. It's head is like a Zippleback's, and its body, legs and feet are like a Nadder's. It has spines like those of a Zippleback too, and has a long tail. Scuttleclaws come in a large variety of colors (green, purple, reddish-brown, yellow, etc.)
Baby Scuttleclaws are possibly the largest baby dragons. They're big enough to be ridden, while most other baby dragons aren't.
Unlike adult Scauldrons, baby Scauldrons can't shoot hot water, just warm water. Just like the Typhoomerang, a baby Scauldron is the size of a baby yak.
Timberjack babies can't tear down large trees with their wings like the adults, but they can break off small branches. Like Typhoomerangs and Scauldrons, a baby Timberjack is the size of a baby yak.
Stormcutter babies are small when they are born, but they grow bigger very fast. They already have their trademark four wings, but have trouble using them, as well as all of the frills on their head and tail.
Snaptrapper babies are always looking for food to satisfy the hunger of their four heads, and every head wants to have all the food just for him or her. Like Typhoomerangs, Scauldrons, and Timberjacks, Snaptrapper babies are the size of a baby yak.
Baby Skrills are aggressive and always want to bite something. They love to fire their lightning; however, it is less powerful then an adult Skrills. They resemble a Night Fury as a baby and someone inexperienced might mistake a baby Skrill for a baby Night Fury.
Rumblehorn babies are very tough and strong. When they are born, they are as heavy as a large boulder, making them one of the heaviest baby dragons in the known world.
Hotburple babies look a lot like the Gronckle babies, even though they are only close relatives. Hotburple babies, just like when they are grown, are very stubborn and lazy. They like metal ores almost as much as a full grown Hotburple (but have a tough time chewing them due to their rounded baby-teeth).
A baby Smothering Smokebreath looks very similar to an adult and is also able to secrete smoke straight from birth. Just like adults, baby Smokebreaths love to steal any metal they can find to help their parents build their nests.
A baby Snafflefang loves to eat geodes almost as much as an adult. Because of their smaller size, they tend to be even crazier for geodes than their parents. As adults Snafflefangs are considered to be very active dragons but this is even more so as a hatchling, this behavior resembles a baby Scuttleclaw.
A baby Flightmare can glow just as bright as an adult after eating glowing algae. However, their teeth are smaller than adults and flightless when young, so the algae must be caught by the parents in order to feed to the baby.
Baby Boneknappers have to find much smaller dragon bones to cover themselves than adults. However the bones that they pick are strong and help protect the baby Boneknapper from its enemies.
Baby Sweet Deaths look similar to Gronckles or Hotburples, but do not grow up to look like them at all. Their big eyes and short teeth make them look somewhat cute, but when they grow up, that cuteness is turned to the stuff of nightmares.
Baby Tide Gliders are much thinner than adults and they haven't grown the big wings of adults yet. However, the horns on their heads are there from birth and their healing saliva is just as potent.
Baby Seashockers have shorter necks, teeth, and tails than adults. This causes them to tend to like to go after smaller prey like capelin or other small fish.
Baby Sand Wraiths are small and very adorable looking. This contrasts with the appearance of adults, who are big and menacing. Babies like to burrow almost as much as adults and they are born in nests underground. The babies of their subspecies, the Desert Wraith, appears similar to its relative, except that is dark grayish in color and has black lines on its wings and tail.
Baby Hackatoos have sharp horns on their heads, just like adults, which they can use to cut into trees for wood. They are prone to getting their horns stuck in the trees they are cutting because they can't cut quite as deep as their parents.
Baby Hobblegrunts have the same large, extrasensory frill of an adult. Being small, they can react quicker than even adult Hobblegrunts. Being young dragons their color changes much more than adults, this is due to the many emotional states of a hatchling.
Baby Woolly Howls have similar fur-like scales to the adults. However, unlike adults, they are a little more cuddly and breathe less powerful ice balls than adults.
Baby Windstrikers already have the horn of adults, although theirs is much shorter and rounded. Their turquoise bodies, wings, and tail are covered in several, yellow circles-like markings. The body of the baby dragon seems to be less thin then that of the adult Windstriker.
Baby Grapple Grounders are shorter and less thin than adults. The horns on the back of their heads are shorter than those of adults as well.
Baby Thunderclaws aren't as large as adults of their species. Like adults, they stand on two legs. Their horns are shorter and stumpier than their adult counterparts.
Unlike most dragons, baby Thunderpedes are capable of flying straight from birth. Their horns are shorter than those of their parents, but they still have as many legs as adults do.
Baby Moldruffles appear very similar to adults. However they have shorter horns on the back of their head and the resonating horn on their head is much shorter. From birth they already have most of the characteristics of adults, such as a fan-shaped tail and similar wing shapes.
Compared to those of adults, baby Mudrakers have horns that appear like two, large bumps instead of a single horn. However, they already have their characteristic sail and can already fire sonic blasts.
Baby Screaming Deaths appear bigger than most other baby dragons (the largest of any baby). However, their tails are much shorter than those of most baby dragons, even those of its subspecies, the Whispering Death. Its eyes are huge, some of the biggest of any baby dragon. Like adults, baby Screaming Deaths have a short, stumpy horn on their face but cant disorient dragons until they mature, however they are known to torment small squirrels and birds with their shriek.
Baby Night Terrors appear to be a shimmering green color, compared to adults, which are either black or white. They also have three tail spikes on the top of their tails and none on the bottom as well as shorter horns than adults.
Baby Death Songs appear to have smaller frills than those of adults. They may also appear a different color than adults. Some may appear to have eye spots on their wings and no sails on their tail.
Baby Snow Wraiths appear very similar to adults. However, they have shorter spines, a shorter nasal horn, and a shorter horn on their chins. Their thermal vision is not as good as that of an adult which puts them in danger of wild boars and other carnivorous animals, for this reason they must stay close to their parents.
Baby Thornridges appear very similar to adults. However, they have two, curled horns on their head and the spiky frill of horns on the adults is already present on the babies.
Baby Catastrophic Quakens are shorter than adults and have shorter spikes. Their "stinger-like tail" is also shorter. However, they do already have the characteristic three jaws of adults.
Baby Speed Stingers are shorter than adults and don't have any noticeable teeth. Their stinger and crests are smaller than those of adults, and their sting is less powerful. However, they still can run fast, but not as fast as an adult.
Baby Changewings have a much larger head compared to their body than an adult. Unlike an adult Changewing, baby Changewings are normally green in color instead of red and can't change their colors very well.
Baby Sword Stealers look very different from adults as they are bright molten yellow instead of a metallic black. Their skin is also less magnetic, as they don't have to make armor to protect themselves yet as they have their parents to protect them.
Baby Shivertooths have teeth just as sharp as adults, which they use to slice up the food that their parents bring them. They are extremely intelligent, just like an adult but their polar shots are less powerful than adults.
Baby Groncicles have larger heads and eyes compared to their body than adults. Unlike adults, they can't freeze the water around them by swimming through it. Their ice blasts are also less powerful than adults but strong enough to incapacitate Trader Johan's ship.
The rare giant baby Prickleboggles have much less thick skin than adults. Their ice breath isn't as strong as adults either. However, they are still very friendly to other dragons and help protect them from harm.
Baby Devilish Dervishes have shorter tails than adults. Their tail spikes are also less sharp than those of adults and their neck and horns are also shorter than adults.
Baby Windwalkers have much smaller wings than adults. They cannot fly yet and are much less faster than adults. However, they are still very loyal, just like an adult.
Baby Slithersongs appear to have smaller frills than those of adults, with some even having no frills entirely. They has smaller heads and horns than adults.
Baby Sliquifiers are much less quick compared to adults, this leaves them pray to many large Scauldrons. Their acid breath is also not as strong as adults. Their fins and tendrils are also smaller than adults.
Baby Snifflehunches' sense of smell is far less powerful than an adult's. Their fire sneezes are also less powerful, however, they are just as playful and curious as adults.
Baby Razorwhips' scales are much less sharp than adults but strong enough to offer protection. However, their tails can still cut through anything. Their fire however still burns hot, but it's not as strong as an adult's and their tears aren't poisinous until the broad wing stage.
Baby Shockjaws don't have as powerful electrical shocks as adults. They have a much larger head compared to their body than adults and their tendrils are also shorter than adults.
Baby Raincutters still love worms and grubs as much as adults. However, they can't dig for them as well, requiring their parents to dig for them. Their fire blasts aren't as strong as adults and can't withstand water, unlike adults.
Baby Submarippers have a large fin on their tail, which adults don't have. They also have a larger head compared to their body and smaller wings than those of an adult. Their acid shots are also less powerful than those of adults.
Baby Shovelhelms' tail fins and heads are much smaller compared to their bodies than adults. Their chin horns are also smaller and less useful with digging than adults. However, they are still hard workers and like to help their parents build nests and other structures.