A mischievous anthropomorphic monkey boy, Jacko Moneky was a member of the Bruin Boys, created by artist Julius Stafford Baker. He first appeared in the Daily Mirror newspaper's comics section in April 1904. In November 1904 the group began appearing in The Monthly Playbox, a colour supplement in The World and his Wife magazine, and from 1909 until at least 1942 they also appeared in Playbox Annual.
Initially Jacko and his friends attended Mrs. Hippo's kindergarten, but in 1914 Amalgamated Press launched The Rainbow, a comic aimed at young children, and Baker's naughty animals relocated to the new comic's front page, as well as taking up residence in Mrs. Bruin's Boarding School, from which they subsequently derived their joint name, the Bruin Boys. From 1919, while continuing to appear in Rainbow, they also starred in the newly launched Tiger Tim's Tales, later renamed Tiger Tim's Weekly. Additionally, they also appeared in Tiger Tim Annual (from 1922 through to 1954) and Bruin Boys Annual (from 1929 through to 1940), with Tiger Tim rapidly outstripping the other Bruin Boys in terms of popularity. Tiger Tim Weekly ended in 1940, but the group continued to star in Rainbow until its cancellation in 1956, then transferred to Tiny Tots between 1956 and 1959, Playhour from 1959 to 1965, and Jack and Jill from 1965 to 1985.
Of all the Bruin Boys, Jacko is the most likely to prank the group's leader, Tiger Tim, though they remain good friends and the jokes are never malicious. Jacko's twin sister is Jenny Jacko of the Hippo Girls.
Jacko appeared in cameo in League of Extraordinary Gentlemen volume 2 among Doctor Moreau's experiments.