This spell functions just like either giant form I or giant form II (your choice upon casting). In addition to the normal effects of giant form, you gain special abilities based on the form assumed.

Cloud Giant

Breath Weapon (Su): You can breathe a 40-foot-long cone of thunderous noise once every 1d4 rounds. Each creature caught in the cone must make a Reflex save (DC 10 + 1/2 caster level + your Constitution modifier) or take 10d6 points of sonic damage. A successful save halves the damage.

Immunity to Sonic (Ex): You are immune to sonic damage.

Ettin

Immune to Sleep (Ex): You are immune to sleep effects.

Superior Two-Weapon Fighting (Ex): You do not take a penalty on attack or damage rolls for attacking with two weapons.

Fire Giant

Breath Weapon (Su): You can breathe a 40-foot cone of fire once every 1d4 rounds. Every creature caught in the cone must make a Reflex save (DC 10 + 1/2 caster level + your Constitution modifier) or take 10d6 points of fire damage. A successful save halves the damage.

Resistance to Cold (Ex): You burn with internal fire, which gives you cold resistance 20.

Frost Giant

Breath Weapon (Su): You can breathe a 40-foot cone of cold once every 1d4 rounds. Every creature caught in the cone must make a Reflex save (DC 10 + 1/2 caster level + your Constitution modifier) or take 10d6 points of cold damage. A successful save halves the damage.

Resistance to Fire (Ex): You have a core like ice, which gives you fire resistance 20.

Hill Giant

Earth-Shaking Bellow (Su): Once every 1d4 rounds, you can loose an earth-shaking bellow that functions like an earthquake spell, except that the area is a 40-foot cone-shaped spread directed away from you.

Meld into Earth (Su): At will, you can meld into earth (but not solid stone) as though using the meld into stone spell, except that you can remain in the earth for as long as you wish (up to the duration of jotunblood form). In addition to the effects of the spells listed in the meld into stone description, a move earth spell cast on your location while melded causes you to be expelled from the earth and take 5d6 points of damage in the process. While melded with earth, you heal 1 hit point of damage per round, as if you have fast healing 1.

Ogre or Merrow

Greater Darkvision (Ex): You have darkvision with a 120-foot range.

Stunning Blow (Ex): Once every 1d4 rounds, you can imbue your melee attacks with stunning force. A creature damaged by such an attack must succeed on a Fortitude save (DC 10 + 1/2 caster level + your Strength modifier) or be stunned for 1 round.

Stone Giant

Damage Reduction (Su): You gain damage reduction 10/adamantine.

Stone Calling (Su): You can cause any rock within 1,000 feet to fly at a foe simply by calling to it. The rock must be unattended and of a size that a stone giant could normally lift and throw. Resolve the attack as though you were standing where the rock is and throwing it at the foe, adding 1.5 times your Strength bonus to damage as normal. You can even use this ability to hurl rocks at creatures you cannot see, including foes that have total cover from your position. However, you must guess where such foes are, and even if you guess correctly, you have a 50% miss chance.

Storm Giant

Breath Weapon (Su): You can breathe a 40-foot cone of lightning once every 1d4 rounds. Every creature caught in the cone must make a Reflex save (DC 10 + 1/2 caster level + your Constitution modifier) or take 10d6 points of electricity damage. A successful save halves the damage.

Resistance to Sonic (Ex): You are inured to thunder, so you have resistance to sonic 20.

Troll

Great Rend (Ex): When you hit with both claw attacks, you rip you foe apart and automatically deal an additional 3d6 points of damage plus 1.5 times your Strength bonus. This ability replaces the normal rend ability.

Statue Form (Su): At will and as a free action, you may turn yourself to stone as though with the statue spell, gaining a hardness of 8. You can remain in this form as long as you wish (up to the duration of jotunblood form). As with the statue spell, you can return to normal as a free action, act, and then become a statue again as a free action.