Remember the Rockman EXE anime that aired about 9 years ago? Well at some point, there were "Beast" versions of past Navis. There are a couple of sketches for these in the Official Complete Works, one fairly detailed sketch is for SparkMan.
Here is my take on Beast SparkMan, in the Gregar form. The only different between this one and the Falzar form is the symbol and wings. Maybe later.
"Oh, but what's different? Didn't SparkMan always look like that?"
Here is a comparison.