Ice Form

 is a Dragon Shout in. The Ice Form shout allows the Dragonborn to shout a powerful freezing force in front of him/her. When the force strikes an opponent, it will simply freeze the victim into an "ice statue" state. The enemy will be completely immobilized and will fall on the ground, while being inflicted with frost damage.

Duration
The effect lasts 20-30 seconds, depending on the strength of the enemy: where a bandit will be frozen for 30 seconds, a giant will be frozen for 20 seconds. Weaker creatures like Deer will simply die by the frost damage before the effect wears off. This effect will not freeze Dragons or Mammoths, but causes some frost damage.

Greybeards variant
The greybeards use a slightly upgraded version of the Ice Form shout. The active effects are as follows:
 * Ice Form: 1 min.
 * Generic Frost Damage: +2 Generic Frost Damage for 1 min.

Trivia

 * If an enemy encased in ice is struck by an attack, the ice shatters, allowing them to recover. This Shout can be used to take one or more enemies out of the fight temporarily, or to gain a few free attacks before they can recover.
 * Ice Form is one of the main shouts the Greybeards will use if they are attacked.
 * If you attack one of the Greybeards when they are in the tower in their courtyard and jump of the edge towards the edge of the mountain, it is possible to become encased in ice and fall down to the Stormcloak Camp below and survive because no fall damage is taken while encased in ice.
 * Using Ice Form on a Frost Atronach will reflect the shout back onto yourself.
 * Using Ice Form can help you pickpocket items that have 0% possibility to take normally. Pickpocket the victim just as he/she is free from the ice form (ice just breaks). Works even on NPC that train you to upgrade skills after you paid them.
 * Will 'free' the torture victims in the Dark Brotherhood's Dawnstar sanctuary, but they will never be hostile and will not flee.
 * Sometimes when freezing an enemy they will still talk (freezing the Greybeards while they teach you whirlwind sprint is a perfect example)
 * This shout is effective against enemies who are on high unreachable places. Because once frozen, the enemy will fall down off the high place and become a frozen dummy.
 * You can freeze 2 or more people who are in the range of the shout.

Bugs

 * If you attack the Greybeards or Ulfric Stormcloak and they decide to use Ice Form, if you have a bow equipped, once you get back up, the bow will be "un-equipped" but you can still "nock" an arrow as if the bow is still equipped.
 * If you fall down from a high cliff when you are frozen with this shout, the impact will not kill you but you will be frozen for about 60 seconds.
 * If you use this shout on an enemy, who is positioned on a mountain slope, or if you use it on a Cave Bear that is leaping at you, they will start flying through the air, in spiraling motions. They will eventually plummet to the ground. The same thing is possible for the Dragonborn and their followers.
 * When battling moving enemies, if your character uses the Ice Form shout on a fast approaching enemy, such as a wolf, the enemy will shoot past the screen and land far from your character.