A Snowy Crystal's body is blue and spherical, with two featureless legs sprouting out of its bottom and a twisted antenna coming out of the top of its head. Its Heartless emblem is present between its two glowing, yellow eyes. The Heartless's body is almost entirely frozen in a block of ice, save for the tips of its legs and antenna. The tip of its antenna is cyan, and the Heartless itself is rather large.
The Snowy Crystal's name references its ice-based attacks, as well as the large ice crystal it is encased in.
Snowy Crystals are powerful, medium-sized Heartless that use ice-based attacks. They will flop around on the ground, causing icy shockwaves to erupt. Some of these shockwaves can even freeze the player. While the best way to defeat a Snowy Crystal is to use the Fire spell, a single aerial attack combo from a high-leveled character can easily deplete a full HP bar if not more. Ground combos should be avoided, as they will leave the player vulnerable to the Frozen status ailment.
Also note that if the Snowy Crystal charges at you and the attack is blocked, it will go on a rampage, causing damage and maybe even freezing everything in its path.