The Third Thing Custom Lego Ideas Set
A Lego Ideas set is an idea for a Lego box set that ties into another product. Fans can build an ideas set with their own pieces (and lots of poetic license!) and present it to Lego as a suggestion for an official Lego set.
This one, developed by a fan, includes several sets with re-imagined scenes from "The Third Thing," and a minifigure mystery bag set of 12. Created by Ali Marri.
Lego Mystery Bag set of 12 Bonus Characters