Principal Guardians are guardian enemies encountered in Borderlands: The Pre-Sequel. It's the second tiers of Eridian flying guardians, it has black body with white armor attachments and able to transform into elemental charged Principals.
- In True Vault Hunter Mode, when spawned, they are renamed Principal Warden and in Ultimate Vault Hunter Mode, they are renamed Principal Exalted.
- When they turn into elemental phase, their name prefixes gets changed after the element as follows:
- In Normal Mode: Corrosive Principal, Static Principal, Cryo Principal, and Smoldering Principal.
- In True Vault Hunter Mode: Caustic Principal, Voltaic Principal, Frozen Principal, and Scorching Principal.
- In Ultimate Vault Hunter Mode: Erosive Principal, Tempestuous Principal, Frigid Principal, and Ignivomous Principal.