It is a recreational gun that one loads with rolled up t-shirts as ammunition. It is used to shoot promotional shirts at groups of people. T-shirts usually unfold when landing. It's impact is generally harmless and does not cause injury to the target.
It has a plastic transparent orange tube, where the t-shirts are loaded. It has a navy blue handle, along with a trigger.
This was then later used by Steven to shoot shirts adorned with Buck's childhood drawing at Mayor Dewey and others at an event, causing panic.
- In "Laser Light Cannon", it contained a shirt reading 'Buy T-Shirt Cannons'. This may imply Greg had not previously used it.