It's helpful to consider rigging when you're designing and modeling your characters, too. (As Robert indicates at the beginning of one of the videos, citing Buzz and Woody.)
For a no-neck character, consider making the head a separate mesh from the body. I did this with my Ballast character:
I think this could work well for your penguin, too, allowing him to turn his head as much as he needs to and greatly simplifying the rigging.