The character known as Coldhands does at first seem to be a wight, with hands black from congealed blood, however unlike those creatures he is actually intelligent and capable of his own thought. He first arrives to save Samwell Tarly and Gilly from an attack by wights in the haunted forest, although it's later revealed he cannot pass underneath the Wall. He commands them to guide Bran Stark to him, and guides Bran to the cave of the three-eyed crow (raven in the show), although again he cannot enter. He's last seen fighting off wights as they enter the cave. Either (or ideally both) of these appearances would be awesome to see on the show, because they're such intriguing moments and he's such a mysterious-yet-cool character (although part of his coolness is his mystery), however we are well past the point of him fitting into the show, so Coldhands (whoever he may be) will have to stay on the page, and hopefully we'll at least find out more about him to make up for it.