hypercritic
/ˌhaɪpərˈkrɪtɪk/
noun
- A person who is excessively or unreasonably critical, finding fault with everything.
- Don't be a hypercritic — sometimes a small mistake isn't worth mentioning.
- My art teacher was a hypercritic who found something wrong with every painting I made.
- The restaurant reviewer was such a hypercritic that no meal ever earned more than two stars.