McDonald's is giving away free food starting Monday through Dec. 24 in a holiday promotion.

The giveaways will be themed after fictional Christmas characters. They aren't 100% free. McDonald's will still require customers to make a minimum purchase of at least $1 using its mobile McDonald's app.

McDonald's will have a different menu for each day for the rest of the month until Dec. 24. The first item will be a double cheeseburger - which McDonald's says is in honor of the Griswold family from "National Lampoon's Christmas Vacation."

Other items will be the McDouble Burger for "Die Hard" character John McClane, iced or hot coffee for Scrooge and medium fries for Rudolph. On Christmas Eve McDonald's will give away free chocolate chip cookies to all customers - without the $1 minimum requirement.

McDonald's has turned sales around by offering limited-time celebrity meal deals. Earlier this year the company partnered with rappers J Balvin and Travis Scott.

Analysts said the promotion was likely McDonald's way of attempting to increase use of its mobile app. Limited rewards programs have been a success for the company - which typically launches offerings during holidays and special occasions.

McDonald's will try and increase customer loyalty with a new rewards program called MyMcDonald's available to both walk-in and online customers.