imaginator
/ɪˈmadʒɪneɪtə/noun
One who imagines something; a user of the imagination.
Origin
Late Middle English; earliest use found in John Metham (fl. 1448). From classical Latin imāgināt-, past participial stem of imāgināri imagine + -or. Compare post-classical Latin imaginator maker of images or statues, forger, contriver.