In BFB, numbers appear to be more sloppily hand-drawn figures of their symbol. Unlike normal characters, Numbers are hand-drawn. They are drawn with a thick black outline, with one uniform color. Their eyes consist of a black dot (pupil) and the white circle surrounding it (sclera). Their legs are also different, being drawn with width and a lighter color than their body.
In "X Finds Out His Value" (canonity is debatable), numbers appear to be more geometrical, drawn with straight lines and curves.
Numbers seem to share a close relationship with one another, rather with non-numbers. Numbers also like to host competitions, or "games".
Numbers seem to be more flexible than objects. Being round and bulbous, numbers seem to be made out of a squishy material. From character to character, the material varies. Four has squishy material (as seen in BFB 1 when Liy squished him) and X has a dry sponge material (also as seen in BFB 1). The rest of the number's materials are unknown.
Numbers seem to have a range of abilities, greatly differing from the cast.
- Screeching (with adverse effect)
- Shooting Laser Beams
- Reality Warping (Making objects suddenly appear)
- Malleable body and limbs
- Mutilation (Morphing objects)
- Sucking up contestants
- Super Speed
- Dismemberment (Cutting off X's leg)
- Cloud manipulation
Numbers are able to perform a mathematical operation with each other, and other number-like objects. In "Four Goes Too Far", Four is multiplied with Donut (representing 0), with X being a multiplicative sign.
*Is not an actual number, but treated as Zero in some cases
- When Four and Donut were multiplied, Four was found as goo inside of Donut. This may mean when any number is multiplied by 0, they are combined into 0.
- Numbers seem to come from another realm, outside of the BFDI space.
- In "Enter the Exit", when Four goes to eliminate Roboty, he has the old straight outline he had in XFOHV.
- Seven appears as a recommended character in multiple BFB episodes.
- Six also appears as a recommended character is BFB 14.
- In addition to Six and Seven, there are also recommended characters who appear to be letters like X, despite never confirmed as XFOHV characters, such as Y (pronounced "whY" in its recommendation), I and D.