Board Thread:Manga/@comment-151.231.104.172-20150824001325/@comment-105.154.58.128-20160205213721

MT has always had black eyes like Ymir though, Isayama confirmed this in an month interview months and months ago.

The translation in relation to Ymir and Mt’s eyes:  “Suruga asked why Titan Ymir’s irises are completely black because it unnerved her a bit. Isayama says Ymir’s are actually not fully dark, but he does draw the Beast Titan’s irises nearly all black so that you can’t tell what it is focusing on - which is an inherently frightening thing. He continues by explaining that normal human beings have whites in our eyes because it’s part of our communication process, as eye contact helps the sharing of ideas and emotions. But with Beast Titan humans can’t read its eyes easily, if at all.”

And about the claws, it’s likely that he always had them and can make them whenever in a situation that he would need them. If you watch him in the most recent chapter, when he first appears he has no claws on his feet, when the focus goes back to him a few panels later he suddenly has claws in place of his nails on his feet. Also, during the castle Utgarde arc, MT was able to climb up Wall Rose by making precise punctures in the wall with his finger tips and toes (made of the same material annie needed to form diamond claws to be able to pierce), and it just so happens that we were never given a look at his toes or fingers during or after he finished the climb. There’s no way he could have done that unless he had pointed tips on his fingers and toes to make those holes. So it’s very likely that Isayama kept that feature of his hidden from us so we wouldn’t draw anymore similarities between him and Ymir titan, who already have many similarities like the black eyes, sharp teeth, elf ears, fur, primate appearance, and the ability to talk.

It also doesn’t make much sense for him to have her claws or eyes if he ate her given what we have seen so far. Titans and shifters don’t really gain the physical attributes of the previous shifter, they just gain some more muscle, whatever special ability the shifter had, and end up looking a little more like a normal human. Both Eren and Ymir can be used as examples of this.

Eren already had elf ears, the odd jaw, and such when he was mindless. After eating his father, his physical attributes remained pretty much the same with the only difference being that he looked more human and had more muscle. He gained none of his father’s physical appearances like his body, etc.

Ymir, also looked pretty much the same before and after. As a mindless titan she already had the black eyes and claws (could be seen on her feet), after eating Marcel she just gained more muscle and looked a little more human, there were no new physical attributes.

The only way MT could have inherited Ymir’s claws and eyes is if they were Ymir’s special ability, which she would have gained by eating Marcel. But, as I pointed out above, she had those as a mindless titan, so they are a physical attribute she has always had which rules them out as things that a new shifter would inherit.