One who concocts; a person who creates or devises something by combining elements.
Concoct + -or agent suffix (variant of -er). From Latin concocere.
A 'concoctor' sounds more sinister than a 'concocter'—the -or ending makes it feel intentional and perhaps deceptive, while -er feels more neutral, showing how English suffixes carry emotional weight.
Complete word intelligence in one call. Free tier — 50 lookups/day.