Lochru

"Even as Camelot flowers, so the seeds of her destruction are being sewn."

- Lochru to Merlin

Lochru was a Druid and vates (a druid seer), who appears to Merlin when he finds him dying in a cave. Lochru warns him that Camelot's seeds of destruction are being sown and of the threat of 'Arthur's Bane'.

Biography
His village was presumably raided by Saxons and that is likely how he ended up dying. Merlin, Arthur, and the Knights of Camelot arrive in a village on their way to Queen Annis' lands to take a secret path to Ismere. Merlin hears his druid name 'Emrys' and immediately follows the direction in which it is coming from. He walks through a cave, then he sees a man beside a pool of water, when Merlin touches his arm and sees the Druid symbol on it, the man, Lochru awakens. Lochru immediately speaks to Merlin about a prophecy that has haunted him for many years called "Arthur's Bane", he claims that Merlin will 'do well to fear it' as it 'stalks like a ghost in the night'. Lochru then falls to his death, but his arm splashes into the pool beside him and inside the water is a vision of a battle in a red sky which shows Arthur being killed by Mordred.

The Great Dragon later explains to Merlin that the prophecy Lochru warned him about should guide him rather than worry him (Arthur's Bane).