Therefore the name may be a portmanteau of the words "gonad" and "monarch".
The Gonarch makes loud, mournful-like sounds when a Baby Headcrab is killed. Small and soft-looking, these Baby Headcrabs are not very dangerous, but they can walk a bit faster than full-grown Headcrabs, attack rapidly and are smaller (almost a third of a full grown Headcrab) and thus more difficult to hit. During the battle with Gordon, it releases undeveloped baby Headcrabs at a rapid rate with no apparent limit to their quantity. The large bag of flesh which hangs from the creature, commonly referred to as its "sack", seems to be a reproductive housing. It can easily withstand massive amounts of projectile and explosive damage, taking even more explosive damage to kill than a Gargantua. The Gonarch boasts a thick exoskeleton, powerful legs, and a large sack resembling a testicle dangling from its underbelly. Little is known about how and when the metamorphosis from Headcrab to Gonarch takes place, as few Headcrabs ever reach that stage.