Therefore anything in the shivering isles, which can come back after death, can be considered a daedra. The baliwog and such have been shown as breeding creatures however, I do not think that daedra breed, so I don't think they are actual daedra, in the technical sense.
This is a very interesting point, relating to one of the Isles' creatures that I feel is quite "mundane". Daedra are immortal, and enter a continuous cycle of rebirth whenever they are banished. Grummites (and by possible association Baliwogs and Scalons) must reproduce, and are therefore not "immortal" in the same sense that a Dremora would be. Did Sheogorath create such a creature simply to be "maddening", or is the Grummite Daedris by very nature of it being created by Sheogorath? Did Sheogorath even create them, or did they simply "occur"?
I wonder if mundane life can spring forth from a Daedric environment, like life emerging on a volcanic, primordial Earth...sure, there are many realms which couldn't support life, like the realm of Malacath. But the Isles seem to be fairly verdant. It stands to reason that things could simply "spring forth", given enough time and an environment that promotes their growth.