|“||Each time Kirby hits the Bumpin' Boo on the left side of the machine, a letter in the word "WARP" will light up. When the pinball hits the Bumpin' Boo on the right, a letter in the word "STAR" will light up.”|
|— Kirby's Pinball Land instruction manual|
Booler is a nearly transparent specter. It has a wicked smile on his face. Booler has a long, wispy tail and often bears its large red tongue in a childish manner. Booler is also shown to be trailed by a paranormal flame in some official artwork, which is a common trait of many stereotypical spirits.
Booler's color varies from game to game. Though Kirby's Dream Land and Kirby's Block Ball are monochrome games, the ghost's artworks portray it as light blue and purple, respectively. Its in-game sprites in Kirby Tilt 'n' Tumble are white.
In Kirby Tilt 'n' Tumble, they do not stick their tongues out, but instead have a tendency to get angry if Kirby bothers them.
To date, Kirby's Dream Land is the only platformer that Booler appears in. The rest of its appearances are all in early spin-off titles.
|“||This unfriendly ghost is one of the speedier enemies in Dream Land. Move into position quickly and then gobble up the ghost with one big gulp.”|
|— Description • Nintendo Power (Volume #39)|
- On the box art for Kirby's Dream Land, what appears to be an orange Booler with a different face and a nose appears on it.
- In Kirby's Pinball Land’s Super Game Boy palette and the instruction manual for Kirby's Block Ball, Booler appears lavender instead of light blue.
- A ghost enemy from the Super Mario Bros. series, called Boo, resembles Booler. However, Boos hide their faces when they are seen by their victims, unlike Booler. Coincidentally, Booler's name in Kirby's Pinball Land was "Bumpin' Boo."