"Sss-About that. So you know the previous heir, Tom Riddle? He kinda killed off the rest of the Gaunt family. He also has no children at present and likely won't in the future as well. I am effectively it for the bloodline of Salazar Slytherin.-sss" I said a little awkwardly.
The great serpent paused and her eyes narrowed violently into little more than yellow lines.
"Sss-He did what!?-sss" she hissed in outrage.
"Sss-He personally cut off the bloodline. In truth my own is stolen, not something I was born with. Still the true bloodline of Slytherin, just not because I am truly his descendant.-sss" I explained truthfully.
"Sss-I don't care about that. Salazar wouldn't either. You obtained this bloodline through conquest yes? Salazar was a firm believer that power was the ultimate authority. I can't believe that ungrateful creature would do something so ridiculous though! The sheer audacity to exterminate your own lineage! Hmph!-sss" the serpent said both dismissively uncaring for the origin of my bloodline and furious at Voldemort.
"Sss-So you actually don't care that i'm not a descendant of Salazar-sss?" I asked genuinely surprised.
"Sss-Why would I? I am bound to the holder of the bloodline, how they obtained it is irrelevant. What I am interested in however is knowing why you have come to this chamber?-sss" she said patiently.
"Sss-I have come to retrieve you actually. I believe you are wasted here. A thousand years and all you have know is this place and what little of Hogwarts Tom allowed you to surface from. I wish to offer you a better place.-sss" I said honestly.
The serpent stared at me with what I could only describe as disbelief.
"Sss-You want to take me from the chamber? The sole place for which I was created to reside?-sss" she asked confused.
"Sss-Indeed. That is my intent. Why? Do you not want to live in a better environment?-sss" I asked equally confused.
"Sss-I certainly won't reject such a gracious offer. But how pray tell do you intend to move me to this place without getting caught? My kind are not tolerated by the vast majority of your kind as far as I understand it?-sss" she asked bluntly.
"Sss-I have a realm all to myself. My own creation in fact. Observe.-sss" I say before stabbing my hand into thin air and pulling open the portal to my realm before stepping through and motioning for her to follow.
The great serpent cautiously slithered through the portal with her tongue flickering out rapidly as she took in the landscape of the realm. I didn't have to say a word as she explored the place eagerly though with clear confusion as she noticed there was not a single other creature in the entire realm.
"Sss-You created this place? Is that why there are no other creatures here? and why the entire place smells of new growth?-sss" she asked astonished and highly intrigued.
"Sss-Quite so. Besides the mountain and water everything you see here was transplanted in. The soil and plants both. I had not yet decided what creatures to populate it with to achieve balance between growth and death. You would be the first. My hope is that you would serve as the guardian and caretaker of this place.-sss" I explained frankly.
"Sss-A generous offer. I will require food however. Something this place lacks utterly.-sss" she said firmly.
"Sss-A simple matter. What kind and how much?-sss" I asked dismissively.
"Sss-I have so far survived on the rodents of Hogwarts and the fish that occasionally swim into the chambers waterways. For the former ten a day suffices.-sss" she said calmly.
'Ten english rats would be between thirty and forty pounds of food every day at a rough weight of three or four pounds per rat. So one African pygmy breed goat a day would suffice.' I theorized.
I looked through the system shop and found one of those in an supply number so high I couldn't reasonably see it ever running out. The goats were cheap too as even with the double market price of the shop they only cost ten coins a piece. I purchased one and released it without hesitation.
"Sss-Is this acceptable?-sss" I asked motioning at the goat that was standing stock still in terror before the great serpent.
She opened her mouth and struck the goat like lightning and downed it whole.
"Sss-More than acceptable. This is the single biggest meal i've had in almost a thousand years. You are far more generous than the previous heir that merely fed me a few cats and owls. We have an accord. I shall remain here and maintain this place and you shall keep me fed.-sss" She said with a slight nod of her emerald head before she slithered over to the mountain and without hesitation coiled like a great jeweled ring around the peak of the mountain.
I felt like this was a little too easy but honestly I could understand why. You had to remember that Basilisk were the "serpent kings" and this one had effectively been living in squalor for over a thousand years. Then I show up and offer an upgrade so monumentally better there was no comparison. All for effectively no other cost to her than lazing about the realm and occasionally straightening things up if something gets out of hand. It didn't take a genius to understand which choice she'd take if she was half as clever as the books and movies painted her to be.