Angel Laboratory

Angel's Laboratory is the ? episode in Season 4. It was the first episode to not be written by Mrs. Yamamoto's and the first episode written by Genndy Tartakovsky. The episode is a parody of Dexter's Laboratory and was suppose to be a pilot for a spin-off series featuring the female Rowdy Hooligan from Across the square which was sadly not pick up for a full series but did become small segment in Next Operation with Genndy Tartakovsky still being the writer.

Plot
Angel completed her work on an invention and went over to where she kept Numbuh 513 (In this episode just called Maria). Angel explain that he put sleepy time medicine in her root beer which put her to sleep, Angel tested the button and turn Maria into a cat. Maria try to get her to change her back to a human with Angel laughing and saying "You look better that way".

Angel put it on a cushion and sit in her chair. Maria knocked the pedestal over and grab the remote and proceed to turn her into a mouse, Maria play with Angel saying "Cats usually eat mice, but I'm just gonna play with my food". Angel grab the remote and turn her into a monkey, Maria grabbed the remote and started running all over the lab with it. She than transform Maria into a rabbit, Angel jump up and grab the remote and turn Maria into a frog. Angel chase after her and change her into a dog, a hamster, a deer, and a gorilla who than proceed to grab the remote from Angel and change her into a cockroach which causes Maria to get scared and threw the remote into the air.

Angel try to get it before it fail in the floor and was crush by it. Maria try to get it before she accidentally step on it and broke it. Angel was angry as she work "3 weeks on that" and said that until she builds another one neither of them will be able to turn back into humans. Maria pick up the piece of the remote and repair it and added a little button called "Normal" and uses it to turn Angel and Maria back into humans. The two promises to never speak of this again and went their separate was until one of Angel's robot pick up the remote and actually change Angel into Dexter and the episode ends.

Characters

 * The rowdy Hooligan from across the square (Angel Saki)
 * Numbuh 513 (Maria)

Trivia

 * This is the first episode in the series to have someone other than Mrs. Yamaoto who worked on Codename Kids Next Door since the first episode of Galactic Kids Next Door (spin-offs included).
 * This is the first episode in the series to only use one voice actor. (Jenifer Hale)
 * Tom Kenny was originally going to narrate the opening scene until it was ultimately drop when the opening scene was change to showing Angel getting ready to go to her lab.
 * The episode is a parody and reimaging of the pilot episode of Dexter's Laboratory which was renamed to change for the fourth episode of season 1.
 * Prior to the episode there was hint in the show that Angel had her own laboratory in her mansion and that the lab at Sak industry was a backup for minor invention with the big laboratory being for Baxter Stockman who was the company's head of research and technology department.
 * This is the second episode in the KND series to use Cel Animation, the first was the Kenny and the chimp pilot. The second time would be for Heroes vs. Villains united only for the Dexter's Laboratory, Powerpuff Girls, and Captain Planet characters and settings as well as the main villain, the third was the KND 20th anniversary episode Operation Celebration.
 * Instead of using music from either Codename Kids Next Door, Ben 10, Ben 10 UAF, or Ben 10 omniverse, it instead uses music from Dexter's Laboratory only adding to this being a parody of Dexter's lab.
 * This is the second episode in Next Operation to not feature the Rowdy Hooligan from across the square as a team and the first episode not feature Sector E as a team and instead focus on one character from each team (Angel Saki and Numbuh 513).
 * This is the first episode to where one of the Rowdy Hooligan from across the square's real name has been said by the other characters. Angel Saki's name has only been seen on her schoolwork, office work, computer, and family tree but never said aloud or by any other character in the show.
 * This is the first episode where Numbuh 513's real name was said by another character since before only her mom and grandmom call her by her real name. Her father calls her "My daughter" or "My little girl" and everybody else calls her Numbuh 513.
 * Both Angel and Maria represent different part of Dexter's personality. Angel represent his boy genius side of him and Maria represent the quick to anger side of him but she mostly the "Dee Dee" of the episode.
 * The episode is dedicated to Christine Cavanaugh the original voice of Dexter in Dexter's Laboratory who passed away back in 2014. The idea was by the Kids Next Door staff as they were making a parody episode of Dexter's Laboratory and made a tribute for her in the form of an episode based off of Dexter's Lab with the original staff and crew from Dexter's Laboratory even going as far as calling the staff's workroom Hanna Barbera.
 * This is the first episode in the franchise to be made by Hanna Barbera studio even if it's in name only.
 * The episode's name is based off the pilot episode's name which was simply called Dexter's Laboratory.
 * The episode was reference in Operation: how we met and again in Operation: Locket, where Maria believe to have lost her locket her grandmother gave her while playing in Angel's Lab 5 years ago.