He is a bit older then Bronze Rineth, it was expected that his rider would become Weyrleader, but didn't
Not much is known about Zirenth, but one of the most important events that involves him is when T'mar is banged against a wall. Zirenth, not able to feel any life in his rider, began to commit suicide by going between. Unknown to him, T'mar is in a coma, not dead, but if Zirenth went between then he surely would die. To stop him, Benden's former Weyrwoman, Lorana, and a harper, Kindan, reached out to him with their minds, forming a bond with him much like a rider's. They kept Zirenth from dying until it could be proven that T'mar wasn't dead.
When Telgar's senior queen, Talenth, rose to mate, Zirenth caught her.