Kirby can roll along as a gigantic snowball, crushing anything in its path.”
— Description • Official Strategy guide
Rolling Snowball is a mix ability from Kirby 64: The Crystal Shards. Kirby will get this ability if he combines two Ice abilities together. With this, a large amount of snow will develop around Kirby, causing him to do a crushing-force roll, then plow and collect enemies. Not only are they trapped in the snowball, but they also get frozen and pop when the snowball is released.
This ability is needed to get a Crystal Shard in Stage 4 of Neo Star. Strangely, it's used to break through a reddish-brown panel rather than a typical blue panel. This ability is similar to the Snow BowlSuper Ability in Kirby's Return to Dream Land.
Kirby becomes a giant rolling snowball, he will roll on until a wall is hit. Enemies will be absorbed into the snowball. After hitting a wall (or pressing B again) the snowball disappears, and any absorbed enemies are launched out as projectiles.
This ability is used almost exactly like Kirby's Return to Dream Land's Snow Bowl; the only differences are that Kirby can jump with Snow Bowl, the snowball is bigger, and Snow Bowl can roll quickly.