In-universe, it is written and directed by Joey Drew, produced in 1929 since after the beginning establishment of Joey's animation studio. The cartoon was made in the early days of the studio whose ending (after the scene where Bendy sees the unknown figure) has not been seen since the cartoon's first run in 1929 and no copies are known to exist.
The cartoon starts with Bendy walking in a field carrying a picnic basket. An arm pops up from the ground and grabs his ankle. He then struggles for few minutes before the skeleton rises from the ground. The skeleton first winks at Bendy after letting him go, then goes back to its grave by pulling the ground over it like a blanket. Bendy becomes a bit confused.
He then looks back to see Boris eating one of his sandwiches. He angrily rolls up his "sleeves" then goes towards Boris, and tries to get his attention. Boris then grabs the picnic cloth and wipes his mouth while Bendy trips off the screen. He continues eating the sandwich while Bendy is trying to get his attention. Bendy then gets an idea to pull a prank on Boris. Bendy sneaks as he grabs a bottle of soda/champagne from the basket then shaking it and aiming it at Boris. Boris then becomes aggravated by Bendy's prank. Bendy then runs away, while the basket landed on Boris' head with raining several sandwiches. Boris then continues to eat.
The camera cuts to Bendy running away to the cemetery and hide behind a gravestone. He checks on a side with the skeleton on the other, and checks the right side. Both see each other and Bendy get frightened, then runs away. Bendy stops at a huge rock panting, while the shadow of an unknown figure covers him. Bendy creepily smiles at the figure, while the cartoon itself later ends by the projector's interruption.
With the other half ending up lost, what really happens next during Bendy's encounter with the unknown figure remains a secret.
- The animation shorts seems to be based off two Mickey Mouse shorts, "The Picnic" and "Orphan's Picnic". It may be also based on Felix the Cat short "April Maze".
- From the game's ending credits prior to update patch 1.3.1 in Chapter 3's first release for Bendy and the Ink Machine, the cartoon's title reads as "Gravestone Picnic".
- When the camera moves to the left where Boris is eating his sandwich, the top right edge of the picnic blanket magically rolls flat by itself, which happens to be an animation error.
- In Chapter 2 of Bendy and the Ink Machine, one of the scene clip appears in the projection screen from the recording studio when turning the projector on from the projection booth, but it is mirrored.
- More scenes can be also seen inside the maze on Level 14 from Chapter 3, but most of them are mirrored.
- This is the longest cartoon short so far, totaling 1 minute and 21 seconds.
- The animation short was actually first released on August 11, 2017 and featured in Chapter 3's reveal trailer for Bendy and the Ink Machine as a first part on theMeatly's YouTube channel. On the unknown date of 2018, theMeatly removed the rest of the Bendy-related videos, including the Bendy and the Ink Machine: Chapter 3 reveal trailer where it include the Tombstone Picnic short. The animation short was finally re-uploaded in Joey Drew Studios Inc.'s channel.