Anke, I think this is Uperoleia. Unfortunately there is no scale and I would have liked to see the hidden colours in the hind legs. The parotid glands are prominent as would be the case for Uperoleia. Happy to stand corrected, but it looks very much like the spotted laevigata on page 724 in Marion's Tadpole book. Eland, can you remember if there was any bright red in the hidden leg surfaces, that would have been very handy to include in your images (handy tip for next time)