Trying out male anatomy
Had a weird dream last night
Pretty much had this guy in it
He's a pure bread dragon, born as a human, his parents gave him up to the human world, believing he was a dud, and would fit better there. They didnt hate him, more didnt want him to be discriminated in the draco-community.
Each phase of his change is noted here whether you can read it or not xD

If not, here:

Samuel

Pre-Change

Believes he's human
Lean Frame
Not very muscley
Slitted pupils
Nocturnal, tired during the day
Smart, but lazy
Eye colour changed depending on whether its day/night

Phase one

Scales growth
Pointed ears
Heightened senses
Small stubs in hair

Phase two

Under developed wings
Hollowing bones
Lighter (not skinnier, but lighter weight-wise )

Phase Three

Slow tail growth
3M long
Razor sharp hooks on tail
Muscle increase
Lung capacity increase ( 5X )
Can hold breathe for around 20 minutes
Small, dull horns

Phase Four

Long, thin horns
Fire breathing develops
Red, sooty fire at first. (Makes him cough)
Set off by: hiccups, Burps, Sneezes, Making him jump
Once mastered, produces a blue flame, but only after a large intake of oxygen

Phase Five

Finger/Toe nails become razor sharp
Clawed foot development
Strengthened muscles & ligaments in legs, making them more shock proof
( Can withstand falls up to 50 meters )

Final phase

Full wing growth
Leathery, partially translucent skin
Stronger flyer at night
Tired quickly ( Flying is like sprinting )
Can glide with ease, but struggles to hover
Fully formed horns curve down back of head (Sharp hooks on topside )