Harry Potter and Dnd crossover
Limits
There is no planar travel scenario, all of the dnd races/monsters/extraplanar beings, have always existed on earth, or in nearby planes. Hidden by the stature of secrecy from mortals.
Yaun'ti revere parseltonques as it works something like charmspeak in PJO/HOO on them. Often their leaders are parseltongues said to be the voices of the world serpent.
The ministry is not aware of pureblood yaun'ti, due to their own ignorance and racist views. "How could a serpent person look like us?"
the yaun'ti kidnap harry upon discovering him, and raise him from age 8 till 11. Likely infiltrating hogwarts when he goes there if they haven't already had infilitration to the facility in the form of students or teachers?
Harry is not in Gryffindor!
Harry views the yaun'ti as family, not as servants or worshipers. Lets face it given his upraising he probably would view anyone who took care of him as family even if they had just kidnapped him.
Recommendations:
the yaun'ti aren't the only race that is infilitrating hogwarts.
What do outsiders think of harry?
Snape as a yaun'ti pureblood?