Do you know whether this library was created as a native KiCAD library, or was it translated from some other EDA program?
@Rene_Poschl described one way to create a footprint like you showed: Create the geometry on a non-copper layer (silkscreen, margin, ECO, etc) using the “Graphics” tools. Save the footprint, then use a text editor to re-define the layer where the shapes are found. (And be careful with future updates to the footprint. Those graphic shapes, unexpectedly appearing on a copper layer, may disappear the next time you “Save” the footprint.)
The second way is to build-up the required shape from multiple, overlapping, SMT pads ALL HAVING THE SAME PAD NUMBER. This technique seems to be mentioned, if not discussed in depth, here on the Forum a time or two per year. Your second example appears to be an excellent candidate for this approach.