Dave, your icon looks like my dog. How funny.
When I lived in Florida, I'd grow various cruciferous vegetables over the winter; Brussels sprouts and brocolli were a success, cabbage actually did form a solid head, but when I went to pick it, it had big bites taken out of it. I mean it looked perfect from the outside, but when I peeled those out leaves, huge chunks were gone from the head. I called the local extension and they said I must have had a gopher turtle (and yes, we found signs of digging under the fence).