Another known Seer is Taliesin, who was the keeper of the Crystal Cave.
Morgause might have been a Seer as well, as she told Morgana that she suffered from nightmares too. It is, however, possible that she just had normal dreams, without prophetic element (The Sins of the Father).The Beginning of the End).
Besides foretelling the future, Seers appear to have similar abilities to those with other magic skills. For example, like Merlin, Morgana can communicate telepathically with others, such as Mordred, and can cast spells.The power of foresight is however not always helpful or harmless. It has been shown on more then one occasion that the very people who have a vision are the ones who are making them come to pass. Merlin made his own vision come true in The Crystal Cave. Gaius claimed that events seen in visions don't always come to pass, as a seer is just able to see one of the many possible futures. Morgause told Morgana a similar thing when she said that there are many futures in this world, some shrouded in mist and other as clear as cut glass. She warned her that the dreams she kept having about Gwen becoming queen where prophecies and she had to do whatever she could to prevent them from happening (Queen of Hearts). However, in the end Morgana was the one who indirectly made this future come to pass, by a consecutive chain of events that began by her enchanting Gwen to an adultery with Lancelot.
A seer's dreams can be stopped from not making him/her sleep at night if an enchanted bracelet is worn, but this only stops simple visions and not prophecies.
|Iseldir||Alive||Unknown, but Druid|
|Lochru||†||Unknown, but Druid|