His cave is filled with stolen wonders.
He was taught to be resourceful at a young age. It's part of not being sloppy. You clean up after your meal, his mother always said. There was more than washing his face and the cold cave floor. There was much more to do to survive.
Clothing is good. You can reuse it, or break it down and make something out of it. He knows another one like him who makes the most beautiful quilts. If you bring her the supplies and a nice meal, she'll make you a quilt too. You can use that every winter. It's going to be cold every winter. You'll need it. Aesthetics aren't important, but it's a nice change. Just because you're a monster in the woods eating people doesn't mean you can't have nice things.
Knick knacks can be useful. Tobacco is ever popular. Not many of his kind like it, but those that do suffer the same addiction as the humans. They can be easily bribed with a few packs, like the younger women who adore shiny jewelry. You never give something for nothing, and those women are young, they could give you something good and useful for a sterling silver necklace. You need car keys to move the car, obviously. Need to get rid of that. Can't have people finding the car and starting to poke around.
The car is another thing entirely. His kind has no use for it, so you have to take it somewhere else. Other demons like cars. He isn't sure why, but they make nice deals, and he never knows what he will get in return for a car. It's better not to ask questions, and just smile and be agreeable, but make sure to show your teeth, you don't want them thinking they can take advantage of you.
But you have to clean out the car first. Money is always usable. There are other useless things like tic tacs and gum. Little pleasures. Cellphones can be found. Those are no good. Those can be tracked now, and should promptly be dismantled and disposed of. For fun, you can put it in another car, going far away and keep the eyes off you, along with a few bloodstained things. Cars are a wild card. Sometimes you get a lot of good stuff, sometimes you just get a pack of gum.
Campsites are another wild card. "Survivalist" bring the bare minimum. Sometimes there is no tent. It's easy to clean up, but he would rather have some amenities, even if it means cleaning up. Drunk partiers do not need to be worried about or cleaned up after. It's easy to snatch one without detection. No one at the party is notices. Screaming cannot be heard over the music and shouting. Some of the lucky ones who are not selected return as genuine campers, curious to see what his woods are like without the loud music. Sometimes they bring good things, and like tobacco, alcohol is easy to trade. There are those who come to kill themselves, alone, or in groups. Sometimes he lets them be and comes for the bodies when they are done. Sometimes he is curious and likes to watch. Many people come in groups, even if just for the day. He knows the ones who come often to hike or photograph. He lets those be usually, along with the families that bring so many modern amenities with them. They bring the battery powered DVD players to soothe the children. They bring so many treats for their young, and sometimes he feels jealous, and that is what drives him. His world is not made up of blinking lights and plastic, but the woods around him, the flora and fauna. Their world is easier. More convenient. They do not need to hunt for food and hunger for months on end waiting. They get to feel full. No matter how much he eats, he is never full.
While his stomach is constantly empty, the cave fills up and needs to be cleaned. He isn't fond of throwing things away. Winters can be unpredictable in harshness and when they will end.
He learns to adapt as it is necessary to survival.