Com = Computer. Typically meant as the computer or game itself is playing that character and you, as the player, will play the other character.

Caleb is also a character in the hit show PRETTY LITTLE LIARS. He is portrayed by Tyler Blackburn.

Probably Mario or Yoshi.

The pictures that were on Lucas loptop where not pictures it was his betting site where he bet on a game using Caleb's money

Nothing because Caleb was never in the books. He's a new character that the show added on.