Last year, Target offered - for the first time - a Lego four minifigure set as a promotion. It featured Lavertus (Chima), Lloyd Garmadon (Ninjago), Swamp Police Officer (City), and possibly the most desirable figure, Superboy (Superheroes - DC).
This is what the 2014 promotional cube looked like (the other two figures are in the back and cannot be seen):
UPDATE: As of today (11/23), Target is sold out online. The promotion is still good in stores, however, as supplies last.
UPDATE #2: As of today (11/24), Target.com has removed the set from purchase. Keep checking your local Target store for the promotional cube.
News is breaking now that the 2015 promotional cube is now available for order online at Target.com!
The figures are (in rank of highest probable collectibility): Lightning Lad (Superheroes - DC), Ninajgo, Chima, and City (officer?).
The main promotion at Target, which runs through 11/25, is buy $50+ of Lego City, Ninjago, and/or Superheroes and you get this cube for free.
However, Target.com has the cube available for purchase NOW!
Even better: 1) This year's set is $9.99 (last year's was $14.99) and 2) Free shipping to your local Target!
(The 20% coupon was corrected and no longer applies to Lego.)
Here's what the cube looks like. Again, you can't see the two minifigures in the back in this picture:
However, Bricks and Bloks, a Lego blog, posted these a year ago. The other two minifigures checked out (in the picture above) so these are probably the other two in the box set: