The invention relates to a cosmetic product applicator (10) with a core (12) having a first end, called proximal end (13), and a second free end, called distal end (16), and a plurality of protuberances (30) protruding from the core (12). The protuberances (30) are molded with the core (12) and are arranged in a plurality of rows extending in the extension direction (Y) of a sleeve (14) extending the core (12). The free ends of said protuberances (30) form two separate enclosures, a first of said enclosures having an outer bulk smaller than that of the second enclosure (E2). The number of rows, called first rows, forming the first enclosure being smaller than the number of rows, called second rows, forming the second enclosure (E2). The invention also related to an associated applicator assembly.