Doomsday was an invasion coordinated by the Director of Ambush Marketing that coincided with the Toon Council Presidential Elections on April 19, 2014. During the event, the Cogs proceeded to invade the entire Toontown Central playground, just after Slappy was announced as president of the Toon Council. A level three Yesman unexpectedly arrived at the scene and made Slappy sad, which then started a battle between the Toons and the Cogs. Toons battled against the Cogs with the use of Flippy's world-renowned Whole Cream Pies. Gradually, stronger waves of Cogs would arrive up until a final showdown with the Director of Ambush Marketing himself had commenced. With the help of other Toons, Flippy managed to end the invasion by defeating the Director of Ambush Marketing with a Wedding Cake. After the invasion ended, it seemed as though the Cogs were defeated, but the Toons had only managed to push them back to the streets.
The event marked the conclusion of Toontown Rewritten's Alpha stage. As this was in Alpha, only a few hundred players with access to an alpha key could participate. However, the event was broadcasted live on Toontown Rewritten's official YouTube channel.
- "Doomsday" was the internal name for the Toon Council Presidential Elections as a whole.
- By definition, Doomsday refers to an event of great danger.
- Doomsday was first mentioned by Sir Max in a blog post titled "Super Saturday: Doomsday" where he announced that the Toontown Rewritten Team would take a week-long break from publishing blog posts to "polish up the Battle System, along with an event before that". No one, however, was really sure of what the blog post meant.
- Doomsday is currently the only event in which the Cogs were present in the main zone of a playground.
- The Yesman that attacked Slappy used a Cog attack only seen that one time, which was known as "Positive Reinforcement".
- A level three Yesman was the first Cog to officially be destroyed.
- Mover & Shakers had their own circular shockwave effect where Toons would get hurt when inside the perimeter
- The fact that Doomsday took longer than the election itself was surprising because of the fact that many players never expected to witness the event at a greater magnitude, let alone see the Cogs.
- In Toontown Rewritten's livestream, the camera view switched from player to view and the transition sometimes stuttered.
- After Hawkheart's crash on the public server in the livestream, Sir Max, Hawkheart himself, Goshi, and McQuack all logged onto a developer server to avoid further crashes.
- Once the main Toontown Rewritten servers were running again, all Alpha testers could replay Doomsday until 2:00PM Toontown Time the next day after April 19th, and fight the Director of Ambush Marketing themselves.
- According to Toontown Central's local Toon Headquarters in a blog post titled "RED ALERT: "Cogs" have Invaded Toontown!", some Cogs managed to escape Toontown Central and venture into other playgrounds, but shopkeepers such as Lil Oldman, Professor Flake, Coach Zucchini, and Shep Ahoy managed to keep them away by setting up traps.
- In Toontown Rewritten canon, Doomsday happened as a result of an old Toontown Online installer video that showed Scrooge McDuck visiting Gyro Gearloose's lab and activating a robot. The Toon Headquarters later reported that Scrooge was not seen attending the election but had gone missing.
- The installer video showed a Yesman being the first Cog to come out of the Manufacturing Machine, which is why the Yesman was the first Cog to arrive at the election.
- Because Doctor Surlee is actually Gyro Gearloose, he presented a sad face as soon as the Yesman saddened Slappy, believing that he was at fault since he created the Cogs.