Lethran is a dark elf assassin appearing in the Dark Ways and Deeds scenario of the Flying to the Rescue campaign in the Heroes of Might and Magic V expansion, Tribes of the East.
Lethran and his hundred dark elf assassins greet Zehir when he enters the underground, and offers to travel with him - fully intending to betray him when it's least convenient for him. Zehir understood what they were planning, and decided to get them killed in battle at the earliest opportunity.
None of the assassins survived their encounter with Zehir.