So this guy is who Xahr has taken up to be his host. Yes he is a krogan just a modified krogan due to how Xahr can alter bodies. A real battle hardened guy by the name of Trox Regg. If don't know, Xahr is a goo like creature which commonly takes the appearance of a nergigante. He is located in the gallery if need to see what he appears like.

This wonderful piece was done by  ~Mr.Bang~ and it's worthwhile to go check his stuff out it's all great stuff. A bit of advice, full screen view helps see even the smaller details.

Character is mine.
Art by  ~Mr.Bang~