A mixing baffle for mixing a fluid flow in a static mixer includes a mixing element support structure extending along a longitudinal direction and a first set of moveable mixing elements coupled to the mixing element support structure. The first set of moveable mixing elements is formed in a first configuration and moves to a second configuration when the mixing baffle is inserted into a tubular conduit. In the second configuration, the first set of moveable mixing elements is optimized for mixing fluids and defines a plurality of undercuts that are difficult to mold. The mixing baffle may also include a second set of stationary mixing elements that interlace with the first set of moveable mixing elements when the first set of moveable mixing elements moves to the second configuration.