Board Thread:Theories/@comment-36359677-20180728000823/@comment-1327106-20180728002233

Marcel had the Jaw Titan and Ymir inherited the Jaw Titan, as expected. Her version of the Jaw looks very similar to the her Pure Titan form though, which is an easy source of confusion. However, the details of the face and body are different. Her teeth and fingertips are sharp in her Jaw Titan form. In her Pure Titan form her teeth are flat like a normal human's and the same with her fingertips.

The anime goes a stretch further. In the anime her Jaw Titan form is compact, but quite muscled, whereas her Pure Titan's arms are thinner and more emaciated.