Pollux

Pollux (Πολυδεύκης in Ancient Greek) is a Greek demigod son of Dionysus and the twin brother of Castor.

The Lightning Thief
Pollux is mentioned by Percy. Pollux is seen first with his brother helping the strawberry plants grow, then at dinner he is seen at Table 12. Percy notices that Dionysus only has two boys in his cabin, Pollux and Castor.

The Battle of the Labyrinth
Pollux and Castor are both seventeen. Pollux sees his twin brother, Castor, die in battle. At Castor's funeral, Pollux tried to speak for his brother, but couldn't choke out the words due to his grief. He lit the funeral pyre, and sat back down mournfully, trying not to cry, Dionysus (their father) is seen following him out to make sure he's alright.

The Last Olympian
Pollux is the only member of his cabin. He fights bravely in battle and calms the other demigods down when they are worried and anxious about the spy amongst them. He is shown to be a good warrior known to have common sense.

He breaks his arm in battle, and Percy insists he not get back into battle, but doesn't tell him why. He tells Pollux it's a "personal favor". Dionysus specifically requested that Percy keep his son safe in a vision Percy had, but Percy didn't want to embarrass him by revealing it. This possibly implicates that Dionysus had been watching over his son after the death of Castor, and perhaps Pollux hadn't dealt with Castor's death well.

Personality
Pollux is level-headed and a good warrior. He is not very close to Percy, Annabeth, and Grover, but is very brave and protective of his brother, his best friend. When he breaks his arm, he was willing to fight with his left hand, though he is only practiced in his right, which would be suicide had he gone back in battle. This shows how much he loved his brother, being willing to die for him.

Appearance
Pollux has a round face like his father, along with his father's dark eyes and curly blond hair (though Dionysus has black hair). He is very good-looking and has an athletic look to him. He and his brother, Castor were identical twins. He is described as being plump.

Relationship with Castor
It is shown that they were very close, and that they loved each other very much. Pollux was brokenhearted and crestfallen at his brother's death, and this helped his fury against Kronos and his monsters, so he had no doubts about him fighting for his brother's memory. Also he was prepared to charge suicidally into battle against the Titans to honor his brother's memory and avenge him.

Abilities
Pollux can control grapes and strawberry plants, using his powers he can grow vines and use them for various things like grapples or restraints, just like his father, except his powers are not restricted. This power is called Chlorokinesis. He and his father are very much alike when it comes to looks, some aspects of their personalities and their abilities.

Trivia

 * Pollux is actually the Latin version of Polydeuces, which means 'much sweeter wine', a suitable name for him as he is a son of Dionysus, the god of wine.
 * He is named after Pollux in mythology, who is the twin of Castor. They were twin sons of Zeus.
 * He is the only greek demigod child of Dionysus known to be alive at the moment.
 * Interestingly enough in mythology, the original Castor was killed while the original Pollux lived.
 * In the solar system, both Pollux and Castor are stars and both in the constellation Gemini, the twins.
 * In ancient Roma Castor and Pollux had one of the greatest temples, located right in the center of the city