|Also Known As:||The Diamair|
|Enemies:|| Morgana Pendragon|
|List of Appearances:||Arthur's Bane|
Morgana was looking for the Diamair, the key to all knowledge, so that she could find out what Arthur's Bane was. With this information, she would have been able to find out how or who by, Arthur will die. Morgana didn't know that the Diamair was in fact the Euchdag, yet ordered the prisoners the Saxons captured, to dig in the mountain to find it. Gwaine saw a glowing in a cave and went to inspect. It was there he found the Euchdag, but was brutally beaten by the Saxons. As Gwaine was injured, the Euchdag found him and cured him of his wounds. When Gwaine woke up, she explained to him that her kind was shunned and hunted for hundreds of years and as a result she is the last one alive. When Arthur and Merlin arrived to rescue Gwaine, the Euchdag fled.
- She has been also known as an 'alien' by fans.
- The Euchdag's gender is not specified, but fans refer to it as female because her anatomy resembles that of a female human. There is no guarantee that her kind have the same anatomy, including gender organs, as humans. Her kind may not even have specified gender.
- According to MacBain's Dictiony (Irish), Section 16, "a fair maid, a charmer: "featsome one", from euchd".