Mattel sends out this update about the DCUC Chem figure:
A lot of fans have asked about the two types of Chemos showing up at retails. Simply put, we made a running change half way thought production to add a bubble piece inside of his chest to create a cool liquid effect. (we actually tried real liquid but that was not working out!)
Check out the pic below to see what this piece looks like (it is not removable). This is a running change and not an intentional variant in our ongoing quest to constantly improve figures in the line!