The Iceball (ビッグアイスダス,Biggu Aisudasu?, lit. "Big Icedus") is a sub-boss in Sonic the Hedgehog 3 that the player will encounter at the end of IceCap Zone Act 1. It takes six hits to defeat it.
Created by Dr. Robotnik, Iceball is a floating frosty machine that floats around the arena with eight snow blocks guarding it. It has a gray main body and three magnetic ends on the body's sides and bottom. It also has what it looks like two eyes and a mouth.
After getting out the cavern of IceCap Zone to the cold external weather, the player encounters Iceball, which flies down into the arena. It then summons eight ice blocks from the snowy grounds which it uses as shield and swoops down in a U shape across the screen once or twice. It will then launch the ice blocks into the air, where they will eventually fall down to the ground. Depending where the Iceball is standing, three ice blocks will usually fall to the left side and two others will fall to the right side. The player cannot destroy the ice blocks and will only take damage when touching them. After this, Iceball will repeat its pattern again.
During the fight, Iceball will be too high to reach at first. The best chance to hit Iceball is after it throws up its ice blocks, as it is at this point where it is at its lowest height. However, the player also has can the chance to hit it normally by using the Lightning Shield as Sonic at the right time or flying as Tails. After six hits, the Iceball gets destroyed and the background gets brighter than before.
In Sonic the Hedgehog 3 & Knuckles, Knuckle will go through his own pathway to the lower part of IceCap Zone Act 1 and face Iceball in a huge cavern. The battle is the same, except the battle may take longer due to Knuckles' low jump height which inhibits him from hitting the Iceball as often as with Sonic and/or Tails.