A character sketch is a brief description, providing information that helps a reader to develop an understanding of the individual. It may include physical characteristics, personality characteristics, reasons for actions the character takes, and more.
A sketch about Scrooge could provide information about his appearance. Early in the story, a description of his looks would need to emphasize the way in which Scrooge distanced himself from others even with the way he looked.
The cold within him froze his old features, nipped his pointed nose, shrivelled his cheek, stiffened his gait; made his eyes red, his thin lips blue; and spoke out shrewdly in his grating voice.
An important part of Scrooge's character is the way he relates to other people, particularly since it changes completely through the course of the story. The sketch should explain that, at the beginning of the novel, Scrooge went through life "warning all human sympathy to keep its distance." This attitude could then be contrasted with Scrooge's attitude and actions at the end of the story, after he has changed into "as good a friend, as good a master, and as good a man, as the good old city knew"
Drafting a character sketch of Ebenezer Scrooge from Charles Dickens' A Christmas Carol could easily begin with Dickens' own description of his main character:
"Oh! But he was a tight-fisted hand at the grindstone, Scrooge! a
squeezing, wrenching, grasping, scraping, clutching, covetous, old
sinner! Hard and sharp as flint, from which no steel had ever struck
out generous fire; secret, and self-contained, and solitary as an oyster. The cold within him froze his old features, nipped his pointed nose, shrivelled his cheek, stiffened his gait; made his eyes red, his thin lips blue; and spoke out shrewdly in his grating voice. A frosty rime was on his head, and on his eyebrows, and his wiry chin. He carried his own low temperature always about with him; he iced his office in the dog-days; and didn’t thaw it one degree at Christmas."
Scrooge, however, didn't start out this way, and any sketch of this character should reference the old miser's earlier, more beneficent beginnings. In Stave II, the Ghost of Christmas Past takes Scrooge to the origins of his professional development, the office of Fezziwig, a character of particular benevolence who was an early mentor to young Ebenezer. Entering this sacred milieu, the now-old and bitter Scrooge reflexively cries out, “Why, it’s old Fezziwig! Bless his heart; it’s Fezziwig alive again!” Scrooge started out with a sense of perspective and with a radically different perspective of human nature than would eventually emerge. A character sketch, then, should depict this evolution from optimistic, joyful young man to the old, bitter, miserly temperament that prompts his series of nocturnal journeys.