"Fuzzy-Wuzzy" was the term used by British colonial soldiers for the 19th-century Beja warriors supporting the Sudanese Mahdi in the Mahdist War. The term Fuzzy Wuzzy is purely of English origin and is not connected with Arabic.
Kipling's poem praises the Hadendoa for their martial prowess, because "for all the odds agin' you, Fuzzy-Wuz, you broke the square". This could refer to either or both historical battles between the British and Mahdist forces where British infantry squares were broken. The first was at the Battle of Tamai, on 13 March 1884, and the second was on 17 January 1885 during the Battle of Abu Klea. Kipling's narrator, an infantry soldier, speaks in admiring terms of the "Fuzzy-Wuzzies", praising their bravery which, although insufficient to defeat the British, did at least enable them to boast of having "broken the square"-an achievement which few other British foes could claim.