A canon is a priest attached to a cathedral. The canons are so called because they lead a rule bound life, "vita canonica".
The two pictures are very different. In Kruspe's drawing (right) the dry Death arrives in a splendidly embroidered coat with a long hood that ends with a tassel. He plays for the canon on a guitar or lute.
In the watercolour above, Death is a skeleton in two shrouds. It's hard to see what he's wearing, but the part that protrudes over his shoulder has neither string nor pegbox, and most of all resembles the end of a bishop's staff / crosier / crook.
Maybe Death comes straight from the bishop? This would explain the words of the canon: "The bishop dies, as well as the canon".
Der Tod zum Domherrn: