The Tweedle Boss is a unused boss from Jazz Jackrabbit 2. They were removed because of their glitches and because they were not finished.
The Tweedles would take the player's gun with a magnet and use it to shoot. In order to defeat them the player was supposed to trick them into shooting each other. The gameplay change required for this boss apparently caused many glitches, so the developers decided to scrap it. They were supposed to be fought in the Psychedelia level.