Happy Birthday, Battle for BFDI! is a short video released to celebrate Battle for BFDI's first anniversary. It was released on November 3, 2018.
The video starts with all the BFB contestants (except David) in the anniversary wheel. Bottle wishes a happy birthday to BFB, and states that she is looking forward to more adventures with all of her friends. She then says that their next adventure would be their most difficult one yet, but they're working hard and can't wait for the viewers to see it. She then says to enjoy the cake for now. However, Remote points out that the cake is made out of cardboard. Bottle then grabs Cake instead, to which everyone starts eating him. Cake then screams out, "I can't handle this torment anymore!"
- Despite the fact that their main goal is to prevent death, Pen, Bottle, Tree and Black Hole are seen eating Cake. However, this is non-canon, so it doesn't count.
- This is the second BFDI short to have Four and X in it.
- When Bottle speaks, the text in the background says Bottle for BFDI.
- David is not present -- Satomi Hinatsu attributes this to him standing behind Dora in the comments section.
- On TV's screen, it shows the classic BFDI Anniversary.
- Out of the objects with arms, Remote was the only who wasn't holding hers up at the start of the video.
- She's also not smiling, along with Pie.
- Liy only has one arm.
- Cake's line is reused from "Four Goes Too Far".
- When the contestants eat Cake, the devouring noises of "Sweet Tooth" used while they are eating the chocolate balls are reused.
- Every character (except David, who is absent in the video, and Saw, who still has her missing handle) has their base designs from the first episode.
- The first tier has all the original BFDI contestants in alphabetical order except David (since he is absent and joined in "Reveal Novum").
- This is one of the few instances where Fanny is seen with a smile.
- This is the third and most recent video made to celebrate BFDI’s birthday, the first being “Thanks for 4 years!”, and the second being “Thanks for 4 years of Thanks for 4 years!”
- So far, this is the only birthday video where the title does not have the words “Thanks for 4 years”, due to this being BFB’s first anniversary.