In literary works, "grumpy" is employed as a versatile descriptor that instantly conveys a character's irritable yet often endearing nature. Authors use it to sketch out personalities ranging from the humorously crusty to the dourly cantankerous, as seen in portrayals like "the grumpy old fellow with the bald head" [1] and the "sour, grumpy, old man" [2]. The adjective not only paints vivid pictures of eccentric figures such as Grumpy Weasel—whose mischievous exploits add levity to otherwise somber scenes [3, 4]—but also underscores a broader mood of isolation or discontent in various settings [5, 6]. Whether used to evoke the familiar grumble of everyday life or to highlight a character's distinctive, sometimes comedic, temperament, "grumpy" enriches the narrative by imbuing characters with a relatable, human quality [7, 8, 9].