Hornoads are small frog-like creatures who will spit nuts at potential who venture too close. Aboard the Biologic Space Laboratories research station they were placed within Sector 1, where they were slowly overrun by the X Parasites, their numbers only barely dwindling (proving them to either be successful r-strategists or simply stocked by the Galactic Federation's science teams in vast quantities) during Samus' time spent within the sector.
As SR388's atmosphere was believed to be wiped out alongside the entirety of the science lab, they are currently considered extinct.
- Metroid II: Return of Samus (First appearance)
- Metroid 4: Metroid Fusion (primarily X Parasite clones, though true ones do appear in Sector 1 backgrounds)