Catty derives from cat + the adjective suffix -y and reflects a long-standing English cultural association between cats and spiteful, indirect aggression.
Deliberately hurtful in one's remarks; spiteful or malicious, especially in an indirect way
Catty is an English formation from cat + -y, first attested in the late 19th century with the meaning 'spiteful, malicious.' The figurative association between cats and spitefulness is old: cats were linked to slyness, scratching, and covert aggression in English idiom long before the adjective appeared. The word draws on a cultural stereotype of cats as creatures that scratch, hiss, and attack indirectly — behaviors mapped
The association between cats and spite is culturally specific. In Japanese culture, cats are generally symbols of good fortune (the beckoning cat, maneki-neko). The English connection between cats and malice is a medieval European inheritance, rooted in associations between cats and witchcraft.