Beth is Claymore No. 2 of both Clare's and Clarice's generation.

Her identical twin sister, Alicia, is Claymore No. 1. She is a product of the Organization's 2nd Soul Link experiment. She wears a special black uniform, like her sister, earning them both the nickname of the Black Ones. Beth looks identical to her twin sister. They share a similar hair style, the only difference in the shape of the bangs; Beth's are cut asymmetrically into a 'v' shape. Both wear the black version of the standard Claymore uniform. They also share the same height.

When Beth is pierced by one of the Parasitic Rods, she Awakens into an amalgamation of Alicia's and Luciela's awakened forms, possessing the body of a large cat with a long, ridged, segmented tail and a head similar to that of the Luciela-like creatures spawned from the Destroyer. Beth's original body is still attached to the cat-like body, though her head is missing. Like Alicia, she has bladed appendages on her head, neck, front legs and torso.

Due to her resemblance to the creatures, Beth's Awakened appearance may have been influenced by the rods. This is further implied after the introduction of Alicia and Beth's successors, who have identical Awakened forms. Thus, Beth's natural form was likely identical to Alicia's. Beth appears to have no emotions and is almost always calm and composed, often with her eyes closed, even when directly attacked. Even without a true "sense of self,” she seems to be deeply attached to her twin sister, Alicia. Her love persists even after Awakening, as shown by her shock and tears after watching Priscilla kill Alicia.

She is completely loyal to the Organization and seems to be more of a follower than her sister since Alicia always takes the lead when they are together. This could be why she was chosen to be the container rather than the attacker for Soul Link. She has yet to speak, with Alicia being the one to talk on the rare occasion that they do need to verbally communicate. She is loyal to humans but obeys Alicia at all times