Urdnot Wreav

Urdnot Wreav  is Wrex's broodbrother, both of them having shared the same mother. He is more traditional than Wrex, placing the importance on his own clan over the krogan race as a whole.

Mass Effect 3
Shepard meets Wreav for the first time in the Hollows, the sacred neutral ground for all krogan, during their attempts to cure the genophage. Wreav objects to the presence of Mordin Solus even when it is mentioned that he was going to cure the genophage, until Wrex headbutts him.

During the land assault against the Shroud facility, where a Reaper was standing guard, Wreav's tomkah was sunk by Kalros, the mother of all thresher maws. He is believed to have died, to the indifference of Wrex, who comments that "he was a pain in the ass, anyway."