Air carrier Captain reported undeclared Hazmat cargo during unloading at destination. Flight crew was not notified or provided documents of Hazmat on board at departure airport.

Narrative

I was on our daily schedule. Upon landing in ZZZ I was unloading and saw that one of the items was a water pump with a gasoline motor (hazmat). I had no Hazmat paperwork and was unaware that the item was on board. In ZZZ1 before departure I was not present to supervise that portion of [the] loading process and by the time I made it out to the plane it had been covered with other freight so I did not recognize it as hazmat. That is where I made my biggest mistake; If I had been there to see it be loaded I would have recognized it as hazmat; and left it off the load. I did speak with rampers about where the weight was loaded in the plane for weight and balance purposes but unfortunately they missed recognizing this item as hazmat. I spoke with both rampers on duty today and gave a refresh on how to recognize hazmat. I was not there to see the item being loaded and the rampers were likely rusty on their recognition of hazmat. I as the pilot need to make sure I supervise the entire loading process and the ramp staff need to be trained/refreshed on how to recognize hazmat.