The Red Skull is a villain in "Happy Birthday, Scooby-Doo", an episode of The New Scooby-Doo Mysteries. He was the disguise of Stuyvesant, Mrs. Vandereel's former butler.
As his name implies, the Red Skull wears a full-face mask that resembles a red human skull with glowing yellow eyes. His costume includes a dark green cape with cowl.
When Mrs. Vandereel bought the Last Hope Diamond, she brought along the curse of the Red Skull, who stole it. So she hired Mystery Inc. to get the diamond back. They followed him to the town graveyard, and Fred Jones and Scooby-Doo managed to capture him. They unmasked Vandereel's own butler, Stuyvesant, who swore revenge.
The New Scooby-Doo Mysteries
Once Stuyvesant got out of prison, he plotted his revenge to steal the diamond again, by getting a job as the director of Here is Your Life, Scooby-Doo, in the guise of Milo Spender. Mrs. Vandereel was a surprise guest who was wearing her diamond necklace, and Stuyvesant revived his Red Skull alter ego to steal it from her. He made Fred look guilty and chased Scooby (and Shaggy Rogers) all over station ZPOP, until the Red Skull followed them up to the roof, where they ended up dangling over the edge. The gang had put all the clues together and found out the truth about Stuyvesant.
- This Red Skull strongly resembles his namesake in Marvel Comics.
- According to Fred Jones, the Red Skull case was Scooby-Doo's greatest mystery.