Reo

A Reo (spelled Rio in earlier media) is a relatively powerful enemy found mainly in Brinstar. They appear in Metroid, its remake, as well as Super Metroid, and in Metroid Fusion as X-hosts in Sector 2. Reos fly back and forth until they see a threat, at which point they execute a swooping dive attack with their talons. They can take much more damage than most other early-game enemies in the first Metroid.

The War Wasps of Metroid Prime are designed similarly to them. Reo were displayed with the capability to wield small firearms in Deceít Du Jour.

Metroid Manual
"These are also pretty strong. They zoom down to attack Samus from the upper walls. The red ones are stronger than the yellow ones."

1986 manga
"Flies from the ceiling toward Samus. The red ones have strong attack power and the yellow ones are weak. Several shots with the normal beam or one Missile will defeat them."

Super Metroid Manual
"These creatures have sharp claws and can withstand several hits."