”Catty wampus [1840; American; chiefly Midlands and Southern U.S.; variant spellings catawampous, kattywampus, cattywampus, caddywompous and catawampus; “a humorous formation” of which the etymology is lost; perhaps the first element of catty wampus with the sense of ‘fierce or destructive’ < a variant on the American folk term catamount, an abbreviation for catamountain, which is ‘a mountain lion’; or perhaps < the Greek root kata- ‘implying disparagement or abuse’; perhaps the first element with the sense of ‘askew or crooked’ < a now obsolete verb cater (1577) ‘to set or move diagonally’ (< Middle French catre ‘four’ < Latin quattuor) and is seen in the word catty corner (originally spelled catercorner and meant ‘four-cornered’), now meaning ‘two items diagonally across from each other’; perhaps the second element < the Scots verb wampish ‘to twist or wriggle’].”
“Still another sense of ‘catawampus’ and ‘catty wampus’ was common in some sections of the antebellum South. It meant goblin, sprite or, sometimes, fearsome beast. Slaveowners were known to warn slaves they thought might be planning to run away that ‘catawampus cats’ were lurking in wait for them. They sometimes also made fearsome noises in the night, which they claimed were the bloodthirsty roars of the catawampus cats.’” Source