You may want to look into "parlor stove" models as they are small, decorative, and will fit nicely into a corner that is lined with covered greenboard for fireproofing. They are designed to warm a very small area (in Victorian days, a parlor, hence the name) and can burn small firewood, coal, cow chips, or pellet corn. (I don't recommend cow chips as they smell nasty when they burn!)
Keep in mind that your roof will need to be protected and the floor reinforced beneath the stove as it will need to be secured to prevent tipping and it will need a fresh air inlet from the exterior to burn properly (and without filling your RV full of carbon monoxide). If it is just for aesthetics, you might like a small propane flame faux fireplace (or electric one like described above) to curl up in front of.