In this case, I got a chart for common wildlife tracks posted to my Facebook account this morning.
So I think we have perhaps hit upon a solution to this problem. The "River Liz" reports which have been reported and sketched by witnesses are not like this but are unwebbed and the toes are more like fingers (3-toed reports of all of these tracks also occur, and could be the result of only partial imprints of the feet)
This being the case it is also possible that some of the "Swamp Monster" reports are actually Giant beavers and that might include both Momo and the Honney Island Swamp Monster, if they are genuine reports. Their heads are big and round, legs short and they generally seem to be more animal than human in nature.
Also there seems to be some indication of small round ears and a cleft upper lip. And the eyes aren't seen from in front because they are actually on the sides of the head.