| Description | Species | First Mention |
| Metamorphosing scavengers of the galaxy | |
| Extinct crab-like broccoli farmers | |
| Small annoying fungible species | |
| Creators of the Hork Bajir | |
| Inhabit the bodies of canines | |
| Intelligent race plagued by insatiable hunger | |
| Saturn-native destroyed by water. Name means 'pet' in the Yeerk language | |
| Parasitic species that inhabit the brains of others | |
| Child-like pawns of chaotic being. Destroy many species | |
| Arrogant plains-dwellers responsible for the Yeerk plague | |