Namihe were large, non-sapient worms indigenous to the planet Zebes. It seems most likely that they move to a location and burrow their heads through the surface, where they can remain sessile - at least for a time - and consume prey without having to expend excess energy from searching for it in the substrate. They seem to prefer extremely hot caverns, indicating that they are thermophilic by nature. This likely stems from an extremely durable exterior exoskeleton, which needs a weapon equal to the strength of a Super Missile for one to crack through it.
They bear an amazing resemblance to Funes, an eyeless species of worm found closer to the surface of the planet that spit their blue-hot fireballs at a slower rate; this seems to indicate that these species are one and the same - either Funes are immature Namihe or it shows sexual dimorphism, although the former is the more likely candidate.
The Galactic Federation showed an interest in the species and brought specimens aboard both the Bottle Ship and the Biologic Space Laboratories Research Station. On the Bottle Ship, a single Namihe attacked Samus Aran alongside a Fune. On the BSL Research Station they were infected and ultimately consumed and then mimicked by the legions of X Parasites roaming the structure.
With Zebes, the Bottle Ship, and the BSL destroyed, it is currently assumed that they have gone extinct until evidence shows that the Space Pirates took them offworld themselves as experimental projects to tamper with genetically, as one would naturally assume they would do with such a powerful predator.