The Destroyer is a massive, intergalactic menace being from another dimension, sealed within Pandora. It appears as a gargantuan, one-eyed beast with a massive mouth and several tentacles. The Eridians, at the cost of their entire civilization, imprisoned The Destroyer within the Vault thousands of years ago.
The Guardian Angel knows of the Destroyer, and that it is actually what awaits those who open the Vault. However, she chooses not to share this information. She appears to want to use the Vault Hunters as a means to defeat the Destroyer. Its defeat causes a planetwide tectonic event, revealing vast stores of Eridium.
In Borderlands: The Pre-Sequel, it is revealed that Jack obtained the Destroyer's eye after its death and used it to create a superweapon for the under-construction Helios Moonbase. Dubbed "The Eye of Helios", it was capable of destroying entire settlements and nearly led to the destruction of Pandora's moon Elpis when Colonel Zarpedon of Dahl's renegade Lost Legion stole control of Helios. The Eye was later destroyed as part of Moxxi's attempt to foil Jack's plan. A side quest involved the Vault Hunters retrieving the pieces of the Eye and attempting to reuse it, but ultimately failed, and the Eye was completely obliterated.
In Borderlands 3, it is revealed that Pandora itself is an Eridian prison designed for The Destroyer known as the Great Vault, with Elpis acting as the key. It survived its encounter with the original Vault Hunters by retreating back into its prison, and now the Calypso Twins aim to harness its power merging with it through the use of their Siren powers. Should the Great Vault be opened, Pandora will be destroyed, and The Destroyer will continue burning its way through the universe. The Eridians willingly gave their lives to bait The Destroyer into the Great Vault, and were sealed inside by an ancient Siren.
- Main article: Destroy The Destroyer
- Some players have experienced a bug that caused The Destroyer to vanish from play when one player exited during the fight. Upon a restart of the game The Destroyer is absent, the mission checked as complete and the Vault Key unobtainable. This could have been caused by a game crash during the fight in some cases.
- On some occasions, the game may crash on kill for a character scoped in on The Destroyer, and the kill will not be counted.
- The Destroyer is very similar to the final boss of Gearbox Software's first game, the Half-Life expansion Opposing Force which went by the name of "Gene Worm".
- The Destroyer's eye, when fired from the Helios, fires in a similar manner to that of the Death Star from Star Wars.
- The Overseer, a Guardian that administrates the Eridian Trials, remarks that the release of The Destroyer has started an investigation to see who was ultimately responsible.