Yumbo were moderately-sized insectoids that have an appearance somewhat reminiscent of a mosquito. This resemblance is caused by a long needle-like section extending from the face, which is most likely a form of proboscis. If this is the case, it can be assumed then that they perhaps fulfilled the same niche role as mosquitoes themselves fill, draining blood or other possible energy/liquid from a multitude of hosts. That being stated, they often were ignorant of Hunter activity, and spend much of their time simply trying to unsteadily aloft on their pathetically small wings. This may have been accomplished in a similar manner to bumblebees. Even though they barely managed flight, they still flie high in the air, moving side-to-side, rarely posing any sort of a problem to typically-sized sapients traversing through the location.
Of note was their proboscis. For unknown reason, several feathery extensions grew outwards from the main shaft, perhaps to steady balance. Not only this, but the proboscis was built to allow these feathers to be rotated, almost like a chainsaw, perhaps indicating that they instead sawed off pieces of flesh from potential prey to consume. The exact mechanics of this implement are not understood.
No known specimens had been taken offworld before the planet's apparent destruction, rendering them officially extinct.
- Metroid II: Return of Samus (First appearance)