Greenfield is a character from The Mask: The Animated Series. He appeared in Mr. Mask Goes to Washington as the President's Aid and head of the Secret Service. After The Mask saved the President's life from a falling building, during his presidential trip to Edge City for its new Downtown center, he was hired into the Secret Service, but Greenfield believes The Mask is dangerous and tries to prove to the President of his chaotic nature, with a little help from Lt. Kellaway.
He was voiced by Kevin Michael Richardson, who is also the voice of Mayor Tilton in the TV series.
- Greenfield's role in Mr. Mask Goes to Washington bares similarities to Sergeant Cole from the other Season 2 episode, The Green Marine. They both have high positions involved serving for the United States, they were The Mask's supervisors when he was working for them, victims of The Mask's antics when provoking him and faced punishment from their higher commanders when accidentally caused trouble for them when attempting to expose The Mask of his troubles. Except, at the end of Mr. Mask Goes to Washington, Greenfield succeeded in exposing The Mask of his troubles by showing the President a video of him taking a bribe, causing The Mask to lose his chance of becoming vice president and forced to resign. At the end of The Green Marine, Sergeant Cole failed in his attempt to expose The Mask's chaotic actions during his court-martial to the judge when the folder he was presenting has a large bite mark on it, (due to The Mask eating it when no one was looking), causing The Mask to get away with his actions and become lieutenant for the US Marines, upsetting Sergeant Cole for a short moment, but he happily joined in a celebratory conga line with The Mask and everyone in the courtroom.