Jonathan Jacobo

"So long, SUCKERS!!!"

- Jacobo escaping from prison

Dr. Jonathan Jacobo is the real main antagonist of Scooby-Doo 2: Monsters Unleashed.

Creating Life
Jacobo always wanted to create real monsters with a book.

Prison Escape
Years later, he broke out of jail on a hay glider to get revenge on them. He dressed up like a female reporter named Heather Jasper Howe and an Evil Masked Figure and turned his old Pterodactyl Ghost into a real monster with a machine he built, along with costumes of some other past Scooby-Doo monsters. They planned to get revenge on Scooby and his friends by destroying them and their hometown Coolsville. Luckily after a big battle with the Tar Monster, Scooby managed to turn the monsters Jacobo had created back into costumes.

Unmasked
Jacobo was unmasked twice before being sent to jail.

Quotes

 * "So long, SUCKERS!!!"
 * "Help me, suckers!"

Trivia

 * Jacobo's plan to get revenge on Scooby and his friends is similar to why Scooby's own Nephew Scrappy-Doo was the main villain of the first live-action Scooby-Doo movie (Monsters Unleashed is the stand-alone sequel to that movie)
 * Both of them plotted revenge against Scooby and his friends after being wronged by them. (Scrappy because Fred kicked him out of the group for peeing on Daphne; Jonathan because they foiled his scheme.)
 * Both of them spend years plotting revenge and dressed up like people (Scrappy dressed up like Emile Mondavarious, Jonathan dressed up like Heather Jasper Howe)
 * Both of them had real monsters to do their bidding (Scrappy met a punch of purple demons, Jonathan turned classic fake Scooby-Doo Monsters into real monsters)