Chewbacca is Han Solo's partner in the Star Wars saga. In Lego Indiana Jones: The Original Adventures, he is a secret character. That means you can find him, but not play as him. You can find him in the level, City of Danger. He'll be in a room that is only unlockable by a character with a book. The glyph panel you need is located where you assemble the truck. The room is almost exactly the same as the Mos Eisley cantina from the 2nd Lego Star Wars game. You'll need Short Round, Maharajah or a Slave Child to get to him.