From A Wiki of Ice and Fire
|Born||beyond the Wall|
|Died||beyond the Wall|
|Book||A Dance with Dragons (mentioned)|
Greyskin was the wolf that was bonded first to Haggon, and then to Varamyr.
Haggon and Greyskin had been partners for a long time. When Haggon was near death, he intended for Greyskin to be his "second life". However, the resentful Varamyr, who Haggon had trained, took over control of Greyskin, forcing Haggon from his body, and prevented Haggon from ever having his second life. As Greyskin was old too, he did not long outlive his old master.