At first, it seems like it'd be best to do some clay bakes rather than final renders but from first glance it seems like they're good concepts but need some work before you go in detailing the busts. The textures seem to be placed as an afterthought - for example the little bit of damage/wear on the chest of the red bust is placed there, but there's nothing else to indicate what it is, etc. The bump/spike in the back also seems random, so in short the character isn't really telling a 'story'.I'm very much a beginner as well, and I keep running into the same issues myself and it has a lot to do with a lack of reference or not using references correctly.Here's an example for the dragon bust - in nature, animals that have 'spikes/horns' are either part of the skeletal system or keratin/hair like a rhino. Horns don't really 'grow' from a circular bump, but are just part of the skeletal structure and skin tends to stretch around it, so the valleys of muscle and skin between two large protrusions should be more pronounced in general - almost webbed in between.For the face, again, this is where real-world reference comes in handy. Animals with small eyes tend to have bad eyesight, so lets say an underground dragon/mole dragon or a deep sea dragon (which is what I assume this is). Real world animals compensate for the lack of eyesight with strong noses and hearing, and its no different in the deep sea where bioluminescence replaces actual light. Exaggerating the features, like the bioluminescent fronds, and maybe pushing more of a underwater predator facial features would really push the narrative. Messy example below - :
I'd put more time into the roughness map, right now they look like made of plastic.