so-and-so
/ˈsəʊənˈsəʊ/noun
(pl. -os)
1- a person or thing whose name the speaker does not need to specify or does not know or remember某某人; 某某事。
1.1
- informal a person who is disliked or is considered to have a particular characteristic, typically an unfavourable one〈非正式〉讨厌的家伙：
nosy old so-and-so!
爱管闲事的讨厌的老家伙！