Grendel is a boss in Lightning Returns: Final Fantasy XIII fought in the Clavis Chamber of the Temple Ruins in the Dead Dunes between Days 1 and 6. It is replaced by Parandus from Day 7 and onwards. Defeating it concludes the main quest for the Dead Dunes.
Grendel could be a threat for players that cannot perform Perfect Block, especially when it uses Breath of Rancor or Séance which inflict debuffs. Its attack is powerful and can deal 3000+ damage. Grendel is more capable with magic attacks. It is weak to Wind-based attacks. Grendel uses Protective Circle at the start of fight which buffs it with Protect and Shell.
The real danger comes if Lightning is debuffed (especially with Pain, Fog, Deprotect, and Deshell), where she cannot use any physical or magic attacks. Grendel can inflict high damage (especially when it uses Séance and then Shadow Clan, which can kill Lightning in one hit).
Some of Grendel's magical attack damage can be mitigated by equipping magic resistance gear. This is especially recommended if Lightning has low HP or if the player cannot perform a Perfect Block. It is necessary to bring any Wind-based attacks to Stagger Grendel faster and give Lightning a chance to use Heavy Slash or Beat Down (which are the locked abilities on the Shadow Trooper garb) which deal 5000–10,000+ damage.
Grendel is one of the three antagonists in the epic poem Beowulf. He terrorizes the mead hall, Heorot, until Beowulf comes to slay him. Said to be the decedent of Cain, he is usually depicted as a foul monster or beast.
Unlike the Grendel in Lightning Returns: Final Fantasy XIII, the Grendel in the myth had a face and body of a gorilla.
- The Grendel and Parandus are based on the model of the Raspatil from Final Fantasy XIII-2, the major differences is that Raspatil has more arms and a flesh tail.