调皮鬼 sounds harsh literally (-
鬼 means ghost/devil) but in practice it is affectionate teasing reserved for children. The -
鬼 suffix turns adjectives into person-nouns with a fond, exasperated tone:
小气鬼 (xiǎoqìguǐ, miser),
馋鬼 (chánguǐ, glutton),
胆小鬼 (dǎnxiǎoguǐ, coward).
