The protagonist in Tolstoy's story "How Much Land Does a Man Need?" is a peasant named Pahom. As stated succinctly in the enotes summary, Pahom's one overwhelming desire in life is to own plenty of land:

The one drawback of peasant life, he declares, is that the peasant does not have enough land: “If I had plenty of land, I shouldn’t fear the Devil himself!” The devil, overhearing this boast, decides to give Pahom his wish, seducing him with the extra land that Pahom thinks will give him security.

Pahom's wildest dreams finally seem to come true when he has an opportunity in the land of the Bashkirs to acquire as much rich land as he could ever possibly wish for.

Pahom can have all the land that he can walk around in a day for one thousand rubles. The one condition is that if he does not return on the same day to the spot at which he began, the money will be lost. 

Pahom's greed leads to his own destruction. He wears himself out trying to cover as much land as possible in his one-day walking circuit.

Pahom's eyes glistened. It was all virgin soil, as flat as the palm of your hand, as black as the seed of a poppy, and in the hollows different kinds of grasses grew breast high.

He keeps seeing choice sections he would like to enclose in his holdings, so he widens the circle until it becomes nearly impossible to make it back to the starting point by sunset. He runs blindly towards the place where he had left his cap as the marker of his starting point, and he just manages to reach his cap in time. But he falls dead of exhaustion.

His servant picked up the spade and dug a grave long enough for Pahom to lie in, and buried him in it. Six feet from head to his heels was all he needed.

Few of us would know what to do with dozens of square miles of vacant land. But there are many other ways in which greed can lead to our undoing. 

Most of the story is told from Pahom's point of view, so he is obviously the protagonist. It is his motivation that drives the story to the very end.