You’re fortunate that @LuckyGuy knows what you’re talking about. Since it’s you asking the question, my guess is that the average reader will assume you want a comparison between humans and one of your esoteric obscure fantasy creatures. If you’re looking for responses, why not ask about people the size of a rabbit?
The smaller size would mean a much larger percentage of body mass exposed to the elements. So there would be extreme variations in physical adaptations depending on climate. A higher metabolic rate would be required to maintain uniform body temperature meaning a higher caloric intake per ounce of animal. The animal would necessarily spend a great deal more time eating than you or I, and if vegetarian, more time still. In fact, the animal’s life would probably amount to little more than avoiding predation and finding enough to eat.