Who is Onestar?

Onestar is the WindClan leader after Tallstar. Onestar's warrior name was Onewhisker, and he and Fireheart became friends when Fireheart and Graystripe brought WindClan back. When Tallstar was about to die, he told Firestar that he did not want his deputy, Mudclaw, to rule WindClan, and he made Onewhisker the leader right before he died.