Bellringer is a Harker. Basically, they are a god.

In this world, the gods are called Harkers, and there are four of them. Bellringer, or their other name, Yarrow. Yarrow is married to the Storyteller, another Harker that rules the world named Meadowlark. Yarrow was sitting in a forest, reading a tale about the Harkers. Before noticing an ad about 4 children called "the Larks" sharing songs and tales about the Harkers.