Most likely small mammals like the mongoose or meekrats or something similar. Birds too I would imagine...though only if caught out in the open...which would be a rare thing...I have heard monkeys are scarred of scorps...but it is only hearsay.
I saw a savannah monitor munching a scorpion on a nature documentary. P.imperator and V.exanthematicus do have overlapping rangers, so it may have been an emp -- it was definitley Pandinus, but I'm not sure beyond that.
I saw a program once , I think it was called "Amphibian" or something, and I saw a pixie frog , (pyxacephalus adspersus) eat a pandinus, a large one, by a pond in africa. I think it may have been staged, someone throwing it out for the frog to eat on que, among eating other things! The frog got stung numerus times on the nose , face , to no avail. He just kept munching away, you could hear its exoskeleton popping!