Chimera is an achievement scalarizing function which combines a priori scalarizing with lexicographic approaches, and is created for optimization problems where the objective is expensive to evaluate. Chimera allows users to organize multiple objectives into a hierarchy, i.e., f = {f i } n i=1 is replaced by f = (f 1 , . . . , f n ) ordered according to a descending hierarchy of importance (f 1 is more important than f 2 , f 2 than f 3 , and so on).