What's in the Sandvich Box?
What's in the Sandvich Box? is an action item given to those who purchased the 1:1 Sandvich toy made by ThreeA Toys either at San Diego Comic-Con 2012, or during the limited Valve Store re-release on December 7th, 2012, October 17th, 2013, and April 19th, 2014, and redeemed the included in-game code. It appears in the backpack as a purple gift box with lime polka dots tied with a fuchsia ribbon. A Name Tag is attached with a question mark.
- At the convention, approximately 300 Companion Squares were sold alongside the 300 Sandvich toys.
- Due to a design issue with the packaging of the 1:1 Sandvich toy released at Comic-Con, a significant number of the slips of paper that contained serial numbers were lost.  This packaging issue has been corrected in the Valve Store Edition by using a plastic serial card instead of paper, and more completely sealing the package.
- Many of the items of merchandise purchased at the booth were signed by the booth attendants; Andrew Wilson, Ashley Wood, Bill Fletcher, Laura Dubuk, Karen Prell and Wade Schin.
- Approximately 200 additional Sandvich toys were released in the Valve Store on December 7th, 2012. The package for these toys is marked as "Valve Store Edition", and the included card with serial code is plastic instead of paper; Aside from this, nothing else is different. This limited re-release sold out in hours.
- On October 17th, 2013, the Omnomnomed Edition of the Sandvich toy was released in the Valve Store. These toys sold out in less than a day, and contained several additional Sandvich Boxes.
- In the early hours of April 19th, 2014, the Omnomnomed Edition of the Sandvich toy was made available again in the Valve Store, complete with voucher for the Sandvich Box. Unlike the previous release of this edition, it did not sell out in less than a day.
- [Undocumented] Added What's in the Sandvich Box? to the game.
- Unlocked the "What's in the Sandvich Box?"