The Freak of Crystal Cove was the disguise of Mayor Fred Jones, Sr.. He used it twenty years ago to threaten the old Mystery Incorporated and their loved ones, when their search for pieces of the Planispheric Disk took them to an old abandoned church, forcing them to leave town, and then used it again when the new Mystery Incorporated searched for it.
He is a lurking figure with a pale face, with long horns on his head. His neck is thin and wrinkled, and his fingers are clawed. He is uncovered to be Mayor Jones. He had blackmailed the original Mystery inc. when they came too close to the treasure of Crystal Cove.
He either enjoys, or has a subconsious habit of reciting strange, threatening rhymes/prophecies to himself, that has to do with the "Curse Begun." It is also implied that he is vicious, cruel, and evil but with some mercy threatening Mystery Incorporated rather than just killing them on the spot, it should be noted that he threatened them crypticly first than directly. When speaking directly to people, he uses rough, childish speech patterns instead of rhymes.
Powers and abilities
He can make shadows look like him. He can also get to places very fast.
Scooby-Doo! Mystery Incorporated
In the present, Angel Dynamite warned the new Mystery Incorporated that he was "still out there", and he was shown to be lurking at the top of an old church. He said to himself that the buried truth would end with him and laughed evilly. (Pawn of Shadows)
He attacked the gang in City Hall. While Shaggy Rogers and Scooby-Doo were at their room, the Freak appeared again, but Ed Machine rescued the two and dropped them off at K-Ghoul. Professor Pericles appeared and he told Mystery Incorporated that he wanted the disk that lead to a treasure and said their was nothing to fear. The Freak of Crystal Cove appeared and Pericles gasped when he saw him and the Freak of Crystal Cove swiped Pericles and he fell on the ground. The Freak snatched the disk from Velma Dinkley. Fred Jones, Jr. grabbed the Freak, but the cliff next to the old church began to fall apart. Fred almost fell, but the Freak saved him and ran off before Fred caught him. Later, Freddie's Mystery Inc. unmasked him as Mayor Jones. (All Fear the Freak)
A different version of him appeared with a threat for the world. He was in Scooby's nightmares. The gang went to the dreamworld to find him, and he seemed to be everywhere. He was revealed to be El Aguirre. (Nightmare in Red)
"From six to one the spell is spun.
No time to run.
The curse begun!"
"The curse begun, but soon they'll see,
the buried truth will end with me!"
"Me prefer Freak. Freak of Crystal Cove!"
- Originally The Freak of Crystal Cove would be called the "Fiend" and had a different design. 
- If he threatened the old Mystery Inc. twenty years ago then this would make him the oldest villain that faced both Mystery Incorporateds, since Danny Darrow's traps were never used against the old Mystery Inc. This may also being forsighting his age.
- In Scooby-Doo! Mystery Incorporated Crystal Cove Online, the Freak was one of the real monsters in the bonus mystery. In the same game, the Freak showed the ability to make living shadows and dissapear with them. However in the series all the shadows were caused by him standing in front of a conveniently placed light..
- He was also green, but in the show, his skin is tanish orange when he tried to get the piece from Shaggy and Scooby.