The pen name Charles Dickens used for his early writings was Boz. He began publishing sketches under this name in the 1830s, before he became one of the Victorian era's best-known novelists.
The name came from Dickens's younger brother Augustus, whom the family nicknamed Moses after a character in Oliver Goldsmith's novel The Vicar of Wakefield. Dickens pronounced “Moses” jokingly through his nose, producing “Boses,” which was eventually shortened to “Boz.”
Dickens's first published fiction appeared in 1833, and “The Boarding House” became one of the early pieces signed “Boz” in 1834. His London observations were later collected in Sketches by Boz, first issued in book form in 1836. The collection helped establish his public reputation for vivid portraits of city life and memorable characters.
A common mix-up is Phiz, the pen name of illustrator Hablot Knight Browne, who illustrated several Dickens novels. Pickwick is a character, while Crummles is a theatrical family in Nicholas Nickleby; neither was Dickens's pseudonym.