What does the idiom 'man or beast' mean?

[Beasty Boy]

English Language Tests, Intermediate level

ESL/EFL Test #404 "English Slang Idioms (139)", question 1

"We should fire Todd. He is no use to ......... or beast. He doesn't know his trade and has a horrible work ethic," Luke said to Christian.

(a) plant
(b) mushroom
(c) man
(d) tool

English Language Tests, Intermediate level

ESL/EFL Test #404 "English Slang Idioms (139)", answer 1

"We should fire Todd. He is no use to man or beast. He doesn't know his trade and has a horrible work ethic," Luke said to Christian.

Correct answer: (c) man
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i wanna explanation for all question please?

Beasty Boy

[Mister Micawber]

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'Man or beast' is an idiom meaning 'anyone'.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber