Aww its cute!! :)

Aw thanks! c:

After I get these guys down, I'm going to draw their babies. So they'll basically just be heads with nubby feet. : D

Hahaha sounds adorable as heck. XD

How do they breed?
By that I mean: do they lay eggs or give birth?

After bouncing this back and forth between my boyfriend and I, here's what we've settled on:

They're a live birth species, who pass their babies in soft little 'bubbles' that pop shortly after birth. The babies themselves are soft, rounded, and develop their tough, durable crests from drinking calcium rich water throughout their young lives.

Live birth spieces? Interesting. They must have womb where young/eggs are developing. But do they have placenta or their eggs hatches inside their bodies? Placenta is a quite interesting creation, it provides food, gases and immunity to the embrion and it removes the fetus discharges while there is a risk to serologic conflict occur plus some diseases passing.

So the crests are made from skeleton parts inrusted with calcium. They probably are made from connective tissue first.
Hmmm. I would consider epidermis product instead: lighter, better to use and I think it's less power-consuming than a bone.
Like, for example, bull.
Though, you may explain this with elephants or pigs, with their teeth (yet they are teeth, not a processus of a cranial bones). Or Triceratops with full crest without lightening windows (even if they could be used as offensive/deffensive weapon, I don't think Ceratopsia crests were a good weapons/shells, they rather served purposes in mating seasons where apparence were more important than the fight, and where the fight was the last resort).
Yet, it's your creature, do with it whatever you wish. I'm giving my thoughts, you may find them interesting and helpful with further developement.

Actually I hadn't put much thought into that! It's certainly been a while since I've extensively thought out a species like that, but you're totally making me want to polish up those skills again. c:

Oo neat! I think I will, I'll do some research into that because it sounds quite interesting, and it would help make them a bit more fathomable, as opposed to a completely unrealistic species. As much as I do enjoy things with purely whimsical aspects, a more in-depth explanation is something I favor a bit more for personal projects. And I thank you for the suggestions and information! It's made me do a bit more research to make them a bit more well rounded in that aspect.

It's totally fine! You may do so as you please; I don't get offended when people offer suggestions or anything like this actually, as long as its done civilly and knowing that the creator still has the rights to stick to their guns. c: For that I say thanks because you're doing exactly that, haha.

Wow, love the armored hide on this guy, and the crest!

Haha, thanks! The armored bits come from Indian rhinos, they're quite neat looking I must say. c:

Yes, I've noticed as much. Very nicely done!