The green Giant Kirby represents the big Slime, a blob-like Minecraft enemy with a green color scheme.
The green Kirby Team's three fighters represents the medium Slimes, the medium-sized version of the big Slimes that are split into three smaller chunks.
The green Tiny Kirby Team's six fighters represent the small Slimes, the smaller-sized version of the medium Slimes that are split into six smaller chunks.
Kirby's favored neutral air attack references the Slime's ability to jump and attack the player in midair.
Other trivia:
This spirit's Grab type references the Slime's green color scheme.
This spirit's Jump ↑ ability further references the Slime's ability to jump.
