Preliminary versions of the weapon were found by data miners starting with Version 4.0.0, under the code name "SuperStamp". It was released on 7 November 2018 as part of Version 4.2.0. The Ultra Stamp was announced on 29 October 2018. A white band around the handle has the Nouveau logo, while the ink tank has the Octopus Oil logo and the Nouveau logo. On the front of the mallet face is a pattern cropped from the SquidForce logo, which is also used as the Regular Battle logo. The mallet face and ink tank change color with the user's ink. Its handle is neon yellow, with the rim between the tank and mallet face on blue. The Ultra Stamp appears to be an oversized squeaky toy hammer with an ink tank formed from a white-capped plastic jug.