A princess readerđ¸ and a Dragon shadow milk đ that steals the princess away to his tower.
Shadow Milk is the "Dragon of Deceit"...often taking a Cookie form so that no one realizes there's a real dragon in their midst, and regularly enjoys spreading rumors and lies! Some of them about him, or just to throw kingdoms into chaos...
This leads him to, at some point, become the new jester in your kingdom...which then leads to the two of you growing close.
As the princess, the royal family keeps you relatively sheltered, very protected...having someone to talk to who can tell you all sorts of stories about other kingdoms, and won't get in trouble for crossing "a line" is a breath of fresh air.
The two of you strike up a bit of a friendship, though of course can't describe yourself as that to others...it wouldn't be proper.
But that doesn't stop you from seeking him out (or him looking for you)...he tells you all sorts of stories and jokes, putting on plays...telling you about dragons and showing you drawings and paintings he happens to have on hand.
He also encourages you to push boundaries...come with him and sneak out of the palace for a little bit! Put on a disguise with him so the two of you can enjoy going around town! And so on.
You off-handily mention how it'd be nice to really leave the kingdom, to see more of the world...to be swept off your feet, really. For a second, you think Shadow Milk grins just a little too widely at your words...
Days later, everyone is surprised when a dragon bursts from inside the castle, laughing and carrying you off in its claws! No one knows how they got in, or what they intend with you...it throws the entire kingdom into chaos.
You, meanwhile, are carefully carried to his domain, and then to a Spire at the heart of it...where he hoards things that are important to him. Lies of his own creation, treasure...and now you.
If he hadn't already shown himself to you, he transforms into the Cookie shape familiar to you. He brought you here because he likes you, after all...and he wants you to like him! Might as well pick up with the friendship you two already have...
Really, you gave him the idea, saying things like wanting to be swept away. (He was probably already entertaining the idea, but hearing you say it really convinced him to go for it.)
Very determined to spoil you. He shows his treasure off to you, gives you books and whatever food you might request...he won't let you go, but he swears that he'll show you around the world once you're a little more...settled in.
Makes a nest for you out of so many mattresses, blankets, and pillows, with curtains draped around the room. He loves to cuddle with you...sometimes in his Cookie form, but also in his natural shape, curling around you and holding you close with his talons like a little plush toy.
On top of the other nicknames, he loves to call you "his treasure" or "his greatest treasure".
Knights and adventurers set out to rescue you...but no one really knows where his domain truly is, thanks to all the conflicting rumors and information he's already woven. And even if they get close to his nest, they'll find themselves lost, confused, turned around...even before seeing the dragon itself.
He's not intending to let anyone take you from him. Knights saving princesses from dragons...such a cliche, really! The sort of thing that really deserves a rewrite, doesn't it?