Heavily pigmented melanocytic neoplasms often present a diagnostic challenge due to their relative rarity and morphologic heterogeneity. With the advent of advanced molecular techniques, an increasing number of these lesions are now being further classified according to their distinct molecular alterations. A comprehensive understanding of both the histopathologic features and molecular landscapes of these tumors is essential for accurate diagnosis, informed prognostication, and appropriate clinical management. Most heavily pigmented melanocytic neoplasms fall within the blue nevus (BN) family, unified by characteristic mutations in GNAQ or GNA11. However, other entities—such as WNT-activated deep penetrating/plexiform melanocytomas and pigmented epithelioid melanocytomas (PEMs)—represent separate biologic groups, despite overlapping morphologic features. This chapter will review melanocytic tumors within the BN family, including recently characterized PKC-fused melanocytic neoplasms, as well as WNT-activated deep penetrating/plexiform melanocytomas and PEMs. Notably, the latter two entities are defined by two-step, phenotype-defining molecular alterations. Although pigmented spindle cell nevi (Reed nevi) are also heavily pigmented, they are not included in this chapter, as they are classified within the Spitz lineage.