UNSC Marine Expeditionary Reconnaissance

Myrmidon is codename for the umbrella of the "second epoch" of SPARTANs, and encompasses the new paradigm behind their creation, the aspects of their creation and function, their accessory equipment and support, and their warfighting philosophy and particulars. It draws from all three previous SPARTAN battalions — from decades of experience with SPARTANs in the SPARTAN-I, SPARTAN-II, and SPARTAN-III programs, integrating detailed post-War analysis on their successes and failures, and combinatorial chemical genetics, chemical biology, and developmental biology to generate the next revolution in SPARTAN warfighting.

Myrmidon operators are listed under "Detachment Four" of UNSC Special Warfare Group SPARTAN, although many in the UNSC Office of Naval Intelligence often label Myrmidons separate from the SPARTANs because of their numerous differences. However, the UNSC Special Operations Command Order of Battle (OB) integrates the Myrmidons into the former SPARTAN command organizational hierarchy.