Harold Hering Knerr was the son of an emigrated German physician. He studied at a Philadelphia Art School and drew his first strip, 'Zoo-Illogical Snapshots', for Philadelphia's Public Ledger newspaper. In 1902 he was employed by the Philadelphia Inquirer, where he created kid strips like 'Scary William', 'Mr. George and his Wife' and 'The Fineheimer Twins', an imitation of the famous 'Katzenjammer Kids' by Rudolph Dirks.
In 1914 Knerr was asked to take over this strip after Dirks' fight with the newspaper. Harold Knerr continued to do the 'Katzies' for 36 years, bringing a humor and originality to the strip that was no less than that of its original creator.
In 1926 Knerr created the complementary strip, 'Dinglehoofer und His Dog Adolph'. With the rise of Adolf Hitler, Knerr was compelled to replace Dinglehoofer's dog in 1936 with a dachshund named Schnappsy.