humorist

Short definition from Wiktionary

Noun

1. 1
   Someone who believes that health and temperament are determined by bodily humours; a humoralist.
2. 2
   Someone subject to whims or fancies; an eccentric.
3. 3
   A humorous or witty person, especially someone skilled in humorous writing or performance.
4. 4
   One who studies or portrays the humours of people.