Grior (グリーズ Gurīzu?) is a former Marleyan soldier who served on Marley's Navy and was part of a survey fleet sent to Paradis Island after the failed Paradis Island Operation. After being taken captive on the island, he begins working as a waiter in a restaurant inside the Walls.
Grior is a young man with dark hair, which is kept closely shaved. He has only been seen wearing waiter's clothes.
Grior seems to be a very cold man, feeling no qualms about betraying Niccolo due to the latter's friendly attitude towards Eldians. He also seems to be somewhat distrustful, believing that Niccolo's friendliness means he has switched allegiances, and seeming unwilling to believe that the wine that has been distributed throughout Paradis was laced with Zeke's spinal fluid.
Grior is among the Marleyan soldiers who are dispatched as part of a fleet to survey Paradis Island, and is summarily captured by the Eldians living on the island. He is put to work as a waiter in a restaurant run by his fellow soldier Niccolo.
When a group of officers from the Survey Corps come to visit Niccolo at his restaurant, Grior contacts the Yeagerists to inform them of the officers' location. After the group arrives, Grior helps them arrest the Corps officers. The officers try to warn them about the threat posed by Zeke's spinal fluid being distributed throughout the Walls, but Grior dismisses the threat as a mere theory dreamed up by Niccolo.