And you are an unreliable observer
The theory of evolution demands that the vast bulk of ALL fossils be intermediates, and that those kinds of changes should be happening naturally at all times, and amongst pretty much all species.
The theory of evolution demands that all species should be in states of flux at all times, and that new species should arise from aglomerations of such minute changes. The one little freakshow item does not cut it. Your freak has HAD legs all the way back.
Where is the evidence of any known type of fish which does not normally have legs, developing legs?