If a Zombie is in the water long enough to start its shaking "drowning" animation, it will still transform into a Drowned mob after leaving the water and stepping back onto dry land, even if it has been back on land for several seconds.
If a Zombie is in the water long enough to start its shaking "drowning" animation, it will still transform into a Drowned mob after leaving the water and stepping back onto dry land, even if it has been back on land for several seconds.
I believe it's intentional that after a certain point they will be guaranteed to become the drowned if they were submerged long enough. I believe this is also a duplicate of another report.