Amergan
The former Druid Amergan is a very unusual teacher. He is a spirit who met Colin MacLeod when he had just revived. Amergan knew a lot about Immortals, and told Colin about his Immortality and The Game. Colin didn’t care about that, and only wanted to kill Marcus Octavius. Amergan followed Colin, and tried to make him stop with his search. He can take the form of small animals like birds or rabbits, and constantly talks to Colin. Who won’t listen anyway.