Enter Grubs dug from the overwintered veggie garden

Preparing the street beds for spring planting I first pulled the winter plants (kale, cilantro), hoed the weedlets, and mixed in complete organic fertilizer (COF). In 30 sqft of garden, I unearthed nearly 40 large grubs of varying designs.

Happy happy day for the hens.

Is there a professional or amateur entomologist out there who can help me identify these guys?  What do they eat? What do they become?