So long, SUCKERS!!!
~ Jacobo escaping from prison.

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


Pterodactyl Ghost

Over the years Mystery Inc apparently caught him committing crimes dressed like a Pterodactyl Ghost.

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.


Jacobo was unmasked twice before being sent to jail.


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


  • 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 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)
      • However while Scrappy might be remediable, perhaps in the long shelved third live-action big screen Scooby-Doo movie, Jacobo doesn't look very redeeming.
  • He was portrayed by Tim Blake Nelson who also plays Samuel Sterns/ The Leader in the Incredible Hulk.