Yumbos are small creatures that live on SR388. Samus Aran encounters them in Metroid II: Return of Samus. They fly side-to-side high overhead, so they rarely pose any sort of problem. They're very mosquito-like in appearance. The feathers along their long needle seem to rotate, giving the appearance of a chainsaw. Their rather small wings don't look as though they could support the weight of their entire bodies, but somehow they barely manage to.
Metroid II manualEdit
"Flies unsteadily in the air."