It's true! Check out this offer below, from this official LEGOLAND page:
Receive a FREE ticket to return when you visit LEGOLAND between November 1, 2014 and January 4, 2015. Present any paid admission ticket at the Our Gift To You kiosk inside the Park, and receive a ticket to return to LEGOLAND California and SEA LIFE Aquarium between January 5 - March 1, 2015.*
* You must request your free return ticket on the day of your paid visit. Free tickets valid only between January 5 - March 1, 2015. Additional restrictions may apply.
Also, remember that you can get a FREE child ticket with the purchase of a full adult paid admission. More on that offer here (link to official page), which is valid at all LEGOLAND parks and LEGOLAND Discovery Centers.