Jonathan Jacobo

"MYSTERY INCORPORATED! This is only the first rung on the ladder of your demise. And this time, you'll be the ones unmasked... as the buffoons you truly are!"

- Jonathan Jacobo as the Evil Masked Figure.

Dr. Jonathan Jacobo otherwise known as Heather Jasper Howe or The Evil Masked Figure is the main antagonist of Scooby-Doo 2: Monsters Unleashed.

He was portrayed by Tim Blake Nelson in his normal form who also portrayed The Leader in the Marvel Cinematic Universe and was portrayed by Alicia Silverstone under the disguise of Heather Jasper Howe who also portrayed Adrian Forrester in The Crush. His voice as the Masked figure was preformed by Scott Mcneil.

Personality
Jonathan Jacobo is a typical mad scientist. He wants to create real monsters and enjoy the rampage they caused. After being caught by the Mystery Incorporated, Jacobo hold a lifelong grudge and vowed to have his revenge on them at all cost.

Heather Jasper Howe seems to be a benevolent, polite reporter at first, but as the story progesses, she reveals her true nature as a fraudulent, untrustworthy person. It is later revealed that she is just a facade of Jacobo.

Past
Jonathan Jacobo is a scientist who always wanted to create real monsters with a book. To do this, he dressed like a Pterodactyl Ghost to rob those he needs for such experiments. Eventually he was caught by the Mystery Gang on one occasion and sent to prison. Jacobo eventually broke out of jail on a hay glider. However, an accident occured in the process and Jacobo is believed to be dead.

Scooby-Doo 2: Monsters Unleashed
In truth, Jacobo is still alive, and dressed up like a female reporter named Heather Jasper Howe and an Evil Masked Figure and turned his old Pterodactyl Ghost costume into a real monster with a machine he built, along with costumes of some other past Scooby-Doo monsters to get revenge on Scooby and his friends by destroying them and their hometown Coolsville. As Heather, he spreaded informations against the Mystery Gang for their failures.

Jacobo later reappeared as the Evil Masked Figure in the climax, controlled all the monsters to fight and kill the Gang. Luckily after a big battle with the Tar Monster, Scooby managed to turn all the monsters that Jacobo created back into costumes.

After his defeat, the Evil Masked Figure is caught and unmasked in front of the public as Heather Jasper Howe. However, the Mystery Gang suspected something and unmasked her for the second time, revealed that Heather is Jacobo in disguise. Jacobo and the camera man Ned who aids Heather were then sent to jail.

Quotes
"So long, SUCKERS!!! Ah, help me, suckers!"

- Jonathan Jacobo escaping prison, only to fall into his apparent death. "I would have gotten away with it... if it weren't for those meddling punks, and their dumb dog!"

- Jonathan Jacobo after his defeat.

Trivia

 * In the Scooby-Doo Show, a character named Johnny is instead the Pterodactyl ghost however all these two characters have in common is the same first name and disguise.