Board Thread:Questions and Answers/@comment-25955276-20160124234218

Well, first off to this theory, Amon's state is unknown. However, we do know this of one other person that was with Amon in his last seen moments: Seidou Takizawa. We know that Seidou and the other people that were with him were taken by Tatara, to be used in ghoul experiments. It could be that Amon was a part of the group. However, Kanou mentions that Seidou Takizawa was his only successful experiment out of the investigator batch, which could mean that Amon is dead. But, there could be the possibility that Amon is alive, since it could be that he ended up being considered by Kanou as a "floppy".

Now, the similarities between the Robed Giant and Amon. The Robed Giant, as stated in his name, is a "giant". He may not be a literal giant, but his title and appearance allude that he is a tall person. According to Amon's wiki page, Amon is 191 centimeters, or about 6'2, which is considered "tall". A manga panel with the Robed Giant's head faceless, but with dark hair, like Amon's. Appearance-wise, the Robed Giant and Amon possess some similarities.

The Robed Giant is seen to be for sure a ghoul, seeing as they have used a kagune. The kagune they use seem to be a Ukaku kagune, hinting that it could be they possess Yoshimura's kakuhou, and were a part of Kanou's experiment. However, there is one odd detail: The Robed Giant is the only ghoul present in the series with a physical deformity, as their right hand only has 3 fingers. In the series thus far, all injuries a ghoul has had could either be healed given time, or were fatal. Since we know that the Robed Giant is a ghoul, it seems odd that he should have any physical deformities. Though, this could make sense if the Robed Giant was Amon. In Tokyo Ghoul, while Amon fights Kaneki, he loses his right arm. It could be that, as a floppy, Amon possessed a defect in his regeneration, which prevented him from regenerating two of his fingers.

If the Robed Giant is Amon, it would make sense since they are the same size, have the same colour of hair, and possess some of the possible traits if they were involved in Kanou's experiments with Yoshimura. 