Lars Quell was the alias used by Anakin Skywalker during his mission on Zygerria. The name "Lars" was likely inspired by his relatives-by-marriage, Cliegg and Owen Lars. While “Quell”, meaning to suppress, put an end to or extinguish, served as a fitting surname, this being Anakin's motivation both personally and professionally on Zygerria (it can also refer to a planet he fought in). To complement his disguise, he wore Zygerrian armor. This is the only recorded time Skywalker used this alias.
The fictional account Skywalker gave to the Zygerrian Queen Miraj was that of a former smuggler of spices and tibanna who had accumulated a large list of enemies in his career and now turned to slave-hunting for better profits. For this reason, he had adopted many names to protect himself, with "Lars Quell" being just one of them. This helped Anakin in protecting his identity and intentions when the queen's distrusting aide Atai came to question his story.
Eventually, Skywalker was forced to abandon the Lars Quell identity when his former master and friend Obi-Wan Kenobi was being offered for auction, and he had to conduct an impromptu rescue attempt, which ultimately failed.