The Nordic Alien was the disguise of Sheela O'Flaherty.
She looks like a female Nordic alien with glasses.
Scooby-Doo! Mystery Incorporated
The Nordic alien, along with the Grey and the Reptoid, stole a GPS in Crystal Cove Mall. It later attacked the Crystal Cove Spook Museum and stole the Space Kook disguise and again with the Grey and the Reptoid stole the Pangea in the Blake Mansion, but was captured by the gang and Sheriff Bronson Stone. (Aliens Among Us)