Birds, in my opinion.

This is a human newborn :

Ugly

But this is even uglier

Screaming featherless chicks, not so pretty.

But when they grow up, it’s a different story :

Stunning, aren’t they?

But really, all newborns are ugly, no matter the species.

Owls. They just look horrific, like something out of a horror movie. They turn into the most beautiful birds though.

Newborn Pandas are pretty ugly, much to my surprise. Once the fur comes in, they’re quite adorable, however.

Animals that have quills give birth to unattractive babies. These include echidnas, hedgehogs, and porcupines. I would also say birds, but they don’t give birth.

One may also find naked mole rats ugly as both newborns and adults.

Marsupials are born underdeveloped, as the mothers needn’t spend extra gestation time when she can let the live young develop in a pouch:

Some placental mammals, like mice, have fairly primitive babies:

A lot of bird chicks aren’t always the cutest:

The offspring of an amphibian, to many, are an unsavory sight:

Once we move away from vertebrates, little is cute. From Echinoderms:

We move to arthropods:

Then on to Nematodes:

Annelids:

And Molluscs:

Flatworm babies are, well.. not exactly magnificent:

Then, we depart from the realms of “ugly” to just plain unrecognizable, with Ctenophores:

Cnidarians:

And the majestic sponge:

So, to summarize: almost all animal babies are not only ugly, but quite hard to even see life and animation in in the first place.

Edit: I changed the Mollusc one from a cute squid to a marine snail larva, just to hammer the point in.

For me personally- baby barn owls.

They don’t look like this forever… They get more feathers and start looking fluffy. But there is a period of time where they look like horrific little demon babies.

Birds!

I’m going to put in a bid on behalf of this fucker.

It’s called a bobbit worm, and it lurks under gravel, waiting to grab luckless passing fish. It’s two inches wide - and up to ten feet long.

This is a baby crow of some kind:

Baby hedgehogs are pretty weird too - they look like mauve plastic hairbrushes.

Well, they say kangaroos have cute babies.

I present to the cuteness court exhibit one…

Item 1:

…Yes. There is an undeniable patootiness to little Mr. Jumpy-legs.

And yes, this cuteness may persist into late youth.

I present to the cuteness court exhibit two…

Item 2:

…I would not waste the court's time in attempting to claim that little Mr. Hoppity's clownishly long feet don't have a certain naive gawky charm.

But.

Ladies and gentlemen of the cuteness jury.

Please compose yourselves from paroxysms of cuteness overload.

Because I must remind you that we are not here today to discuss the cuteness of animal children, but of animal babies.

And those images - and many others like them - are of joeys. A joey is an infant, but not a baby.

As for baby kangaroos… well.

The kangaroo pouch is not where the baby is born, it is where the baby is raised.

And to reach the pouch, the baby must be born, and crawl its way up to the pouch.

So. The question is: what does a kangaroo newborn baby look like?

What crawls its way to the teat?

This does.

Item 3:

Item 4:

Item 5:

Would you, in all honesty, happily clasp that to your breast?

I rest my case.

I wouldn't say they're ugly per but for the sake of answering the question:

This is an adult echidna. Very cute.

A baby echidna

The adorable Wombat

A baby wombat

A full grown Aye Aye

A baby aye aye. Looks more like a grandpa than a baby.

Source: 6 Adorable Mammals with Unbelievably Ugly Babies

Look. It's hard to top the baby parrot and the baby otter or the baby kitties, but seriously, this is -- IMHO -- the cutest baby animal on earth. His name is Moose and he's my parents' new Yellow Lab:

Not that many, or at least not in my opinion.

I’m one of those people who truly believes that almost all animals are cute.

Awkward baby parrots?

Adorable!

Baby cobra that could probably murder me?

So sweet! Look at that little pink mouth! He looks so happy!

Baby rhino that could also probably murder me?

*Squeals from cuteness.*

Teeny tiny alien-like Axylotls?

GOOD LORD YES.

Wrinkly gray manatee with her equally wrinkly baby?

That’s so beautiful!

Chubby lil’ baby hippo swimming with his also chubby and probably highly aggressive mom?

*Dies*

These, though?

Or this?

I think I’ll make an exception. This is where I cross the line.

Still though, they could be beautiful in other ways.

Maggots, for instance, are great at eating away body parts rotted from disease, and lampreys are not only very interesting but also considered a delicacy in many parts of the world.

As the old saying goes, beauty really is in the eye of the beholder.

Sharing my cuteness basket:

• Love Tiger Cubs, they seem to speak with their eyes when they are small too :)

• Mini-Otters:

• "Babe":

• Mini Hedgehogs:

• Mini Guinea-Pigs:

• Baby Pandas:

• Baby Sheep

• Baby Hamster
  

• 
  
• The small turtle
  

• 
  
• Baby Giraffe
  

Babies of every species if you see all are the cutest and the comparison is too difficult. I’m giving some examples-

Koala

Hedgehog

Racoon

Panda

Kitten

Elephant

Lion cub

Goat

Birds

Puppy

The list is too long…

:)

Do upvote!

This is a blobfish:

Oh, mercy *fans self*

Now, it’s not winning any beauty pageants, but it’s not hideous.

But wait, you say. That doesn’t look very blobby?

That’s because this fella…

…is suffering from the effects of decompression.

Blobfish are deep sea creatures that live at depths between 600-1200 m. Much like me after skipping the gym for a few months, the blobfish is a gelatinous mass with soft bones and little muscle.

In these high-pressure environments deep underwater, the low density of the blobfish allows it to go about its daily life. I guess it would make an excellent athlete, since it thrives under pressure.

This is a problem when the fish is brought up to the surface, though, as an animal built for living 1000 m underwater can’t cope with life at lower pressures. With all the structural integrity of blancmange, the fish collapses on itself, and provides le interwebz with clickbait misinformation that will no doubt last for decades.

So no, the blobfish isn’t really all that ugly. It’s just out of its element. We probably wouldn’t be doing so well at the bottom of the ocean, either.

You Have Been Lied To About The Blobfish This Whole Time

Baby elephants :
They are such adorable creatures. Magnus babies totally vulnerable, makes you go awweee...:)

Kittens:

Baby desert cat :

Lion cubs :
I am a huge fan of Simba, you can guess the rest.

Puppies :
Looking at cute puppies, takes all your worries and stress away in an instant.

Tiger cubs :
Cuteness personified.

Baby Pandas :

I don’t know that I’d consider them ugly, but marsupials have always blown my mind. The entire journey, of a Joey (new born “Roo” born only 2 cm long) for example, inching its way “upward” on fur and in to its mother’s pouch where it will suckle on to a teat and grow until its appointed time. Occasionally they’ll still hop in after having grown significantly (appearing much too large to get away with it) for a familiar ride with “Mom.”

They actually resemble a type of brown and alien life form, larger than a “pinworm,” sliding on up it’s mother’s pouch. No one can help it either. It is it’s early start to its first real fight for its life.

Rather amazing to me.

It's probable that "cuteness" is something that only has a meaning to human beings. While there are isolated incidents of animals adopting infants of other species, that appears to have more to do with human interference and matronly tolerance than with an actual appeal. There's nothing corresponding to the nearly universal human reaction to, say, the fennec fox.

The best interpretation I can give is to suggest that human beings anthropomorpize easily: we tend to see other creatures in terms of our own. There's especially a tendency to seek out faces, even where there clearly isn't one, a psychological trait called "pareidoila":

We don't just see faces, we attribute emotions to it. This box doesn't just have a face. It's clearly shocked. Not angry or even surprised: shocked.

The point is, clearly humans are capable of seeing others as distinctively human. And from there, we get to "cuteness". Cuteness is associated with properties of human infants: large eyes, a big head, curvy rather than pointy features, etc. These features can even be exaggerated to the point where they're clearly inhuman and still increasing the "cuteness" response, the same way we clearly recognize the box:

From Anime blog: October 2012

Tying this in to evolution: given that this is common to all humans, it seems likely that there's a genetic component. Since these are features associated with baby humans, and baby humans are almost uniquely helpless and in need of care, it's not unreasonable to think that evolution could select for an emotional response that makes a human being wish to care for a small child.

And that's really all that can be said about it, because behavior doesn't fossilize and we don't have any idea how genes result in behavior and I am exceptionally tired of typing that. This is the very last time I am answering a question involving a phrase like "evolutionary advantage", and I'm not going to be typing that evolutionary-psychology mantra in. I'm just going to hit "decline", and I hope you'll all forgive me for the rudeness, but I've served my time on this "yes, evolution can potentially explain behavior" schtick and I am retiring.

Marsupials have the weirdest babies as they give birth to premature offspring.

I think that kangaroos have the weirdest or strangest offspring.

Yes.

But there are two ways to interpret the question. Do you mean cuter according to us or cuter according to the babies’ own parents?

We think baby animals are cute when they resemble our own cute babies—large eyes, chubby build, clumsy movement, and so forth. Is this a coincidence? Probably not. Babies have those large eyes and chubby features in order to trigger our parental instincts—and the same is true of other species. We have the same instinct (subjectively experienced as “awe, cute!”) and it’s triggered the same way—so we think puppies are cute and adult dogs probably think human children are cute.

The trigger doesn’t always work cross-species. Some baby birds are pretty ugly, for example, but their parents probably think they’re cute.

But species that don’t have parental behavior don’t need to be cute as babies, and they often aren’t, except coincidentally. Their parents probably don’t think they are cute.

Baby duck wants to go swimming

Baby flamingo tries to be an adult

Hey yo!

This baby panda might have a sweet dream.

Baby hedgehog

Baby corgi with attitude

Baby cat

Pigeons,

And parrots

Come to mind, similarly butterflies and moths are a lot less cute as babies

Among vertebrates, some baby birds are pretty unappealing. This is a baby crow:

and this a baby parrot:

There are number of animals who seem ugly when young, but grow up to be glorious beauties.

I will show one example that is from my life:

Here is the kitten who was considered ‘ugly’ in a shelter where from I adopted her. Because of that ‘ugliness’ no-one ever wanted to adopt her and she was scheduled to be put down soon. I thought she was cute though. Good I have appeared there in time. Here is her pic when she was young (already at my home):

Here is my Midnight growing up:

And here she is how she looks fully grown:

She looks the same today. Midnight is 11 years old now and we love her to bits.

Certainly. There’s nothing cute nor adorable for instance about baby flies, which we call “maggots.”

And I certainly am no more fond of baby cockroaches than adults.

Most people will also not coo over baby spiders or scorpions.

Horses by far are my favorite animal, but I think newborn foals (I mean new newborns, right out of the hatch!) are bizarre. They look emaciated, their ears are sort of droopy, the skin around their eyes is all pale, are about 60% legs (which they haven’t figured out at all!) and are sopping wet. Give them 24 hours, though. They’re dried off, the ear cartilage has stiffened, their eyes have darkened up a bit, they’re beginning to catch on as to how legs work, and they plump up, thereby becoming the most adorable babies in the animal kingdom. And those high-pitched baby whinnys? My heart melts.

Of course, were any of us really prizes when we’re first born?

well kangaroos comes to mind

And here you have a newborn kangaroo baby

And an adult kangaroo

Even if the adult is not that super cute i would say it is still cuter than the babies.