In Chapter 19, Edwin, Garvey, and Cole see a solitary animal loping along the shore... what is it?

Edwin, Garvey, and Cole see a lone wolf loping along the edge of the water.

“Hey, look,” he called, pointing across the bay.“Is that a coyote?”
Edwin and Garvey looked up at a ghost like figure moving along the far shoreline.“It’s a wolf,” Edwin said.“A big one.”