Which character consistently declares, "I will work harder"?

The phrase "I will work harder" is consistently associated with Boxer, the strong and loyal cart-horse in "Animal Farm." Boxer embodies the work ethic and dedication of the working class, and his mantra reflects his unwavering commitment to the success of the farm and the ideals of Animalism. Despite facing numerous challenges and exploitation, Boxer believes in the power of hard work as a means to achieve a better future for all animals on the farm. His character represents the theme of the burden carried by the proletariat, illustrating how the hardworking individuals often bear the weight of others' ambitions and fail to recognize their own exploitation.

The other characters do not embody this same level of relentless work ethic or make this specific declaration, reflecting their different roles and attitudes toward labor and leadership on the farm.