Remember the very homely Cardinal? (here) The bird continued to follow the parents long after he was able to feed himself. We often saw him at the feeder alone, stuffing his beak. If either parent came by, he would hop to them and beg for more food. I am sorry to report that he has joined the legions of the obese. He is not fluffing up his feathers like a sick bird. He is alert, has no problem swallowing, no problem flying, and shows no sign of illness.
Maybe not quite so homely, but really really large.
He still has a rather goofy look that makes him easy to identify.
This shot of the feeder compares the large cardinal to the chickadee. Note how the feeder is leaning under the cardinal's weight. I assure you he has no idea the chickadee is there. If he did, he would chase it away immediately.
The cardinal is often the first bird to the feeders when we put them out in the morning. And he and his parents are almost always the last ones to grab a bite before we bring them in.