I wouldnt like to Guess, certainly not without a clear photo and lots of background info, But I imagine Most folks first thoughts would be possible MBD.
That said, I do have a theory/question of my own about veiled casques.
We know the casque is a bony part of the skull, but how much is known about bone developement (skull in particular) in young chams?
With some animals, bones of the skull dont develope as fast as the rest of the skeleton,
as the animal grows toward adulthood, the skull bones become more solid/dense/strong.
By adulthood, the skull is pretty much solid.
Consider the skull of a baby Human, there is a soft spot that strengthens and hardens as the baby grows.
My theory is that even in a healthy young chameleon with no MBD or other deficiency,
The casque part of the skull may still be undeveloped, that is, its there, but not as strong and solid as other bones.
Over time, perhaps from normal pressures (ie dont they love to push their way through dense branches (and under them) may exert forces on the developing casque, causing it to grow deformed. ?
Note: The shells of freshwater turtles exibit these same characteristics. Tiny turtles held incorrectly (by the edges of the shell) sometimes end up with a wonkly shell around the edge . (carapace).
Just a few thoughts! I have recently moved mine to a new cage, much less densly planted (branches) than the last. In his last he was always pushing between branches with his casque and I was concerned about damage.
Best wishes with your cham.
