Bowser

"The curse begun, but soon they'll see, the buried truth will end with me!"

- Bowser revealing his true nature.

"Two years after they left Grenda tried to return to California, by that time he and Judie had married and she'd given birth to a baby boy. I had to stop you, I took you in and told them you'd be safe, as long they never returned again."

- Bowser confessing the truth behind his adopted son.

Bowser is the main antagonist of the 2016 animated film, The Magic Park. He is the manipulative and arrogant dream demon who plotted to take over New York and brainwashes all the kids with a massive army of animatronics at his command.

Biography
Introduced as the Mayor of the town New York, Bowser is a greedy mayor who takes opportunity of the paranormal events in the town for his own money. Because of this, along with the fact that he constantly forbids his son, Nickland, to hang out with the Mystery Gang, their relationship slowly cracks worse and worse. Thanks to Nickland's tricks, Bowser accidentally kills himself in the explosion after digesting soda and mints.

Years later, he revives as the spirit owner of the Magic Park, a amusement park trap in Oregon that competes with the Toy Factory. When Leela tries to flirt with him, he pretends to be charmed, but the minute the two are alone, Bowser subdues him, webs him up and drags him into a cave to eat him. He shows his true form to him while bragging about how he fell straight into her trap and how he will eat him just like she did to countless other men, but not before he reveals his true colors, disguised as The Freak of Crystal Cove and attempts to attack the Mystery Gang, along with the rest of the teens, and make the Magic Park a haunted place within each of the gang's mysteries. Bowser then brainwashes all the kids through the song "God's Bad Creatures".

However, Nickland, Darlene, Fat Burton, and Grenda manage to save Stan and leave Bowser stuck under a giant statue's boot. His final fate remains a mystery. While he was left trapped under a statue's foot, he was not killed, so it is possible that he could use his human form to convince a Magic Park visitor to free him later.

Personality
He was the mayor of California and the "surrogate" father of Nickland Bowser. On the surface, he seems to only care more about making money from the town's mysteries rather than solving them, which conflicts with his son, contributing to an already awkward relationship.

In reality this is a cover for a much darker and obsessed personality, one who has gone to great lengths to complete the curse. He forced the original Comedy Gang to leave the Magic Park.

Bowser is also shown to be a selfish and greedy opportunist. He will do almost anything to make the Magic Park into a haunted place as desire for kill all the children and teenagers. He takes any of the paranormal and bizarre events that happen in the Magic Park as an opportunity to promote the town's popularity regardless of the consequences and thus, he will willingly turn a blind eye in favor of reaping the benefits that they bring until it is too late. In turn, his relationship with his son has become turbulent at best, with Nickland quickly (but surely) realizing how selfish his father really is.

He is also ruthless, selfish, hateful, argumentative, destructive, headstrong and treacherous spirit towards teens. He wants to make the Magic Park a huge haunted place within each of the gang's members, because it plots to brainwashes all the kids as slaves.

Trivia

 * His true nature is quickly foreshadowed by his glasses, which resemble the eyes of her true demon form.
 * Despite being the main antagonist, Bowser has less three hours and ten minutes of screen time.