Aside from some proportion issues (size of the muzzle) these are looking good and solid.One thing; The side of Meat-heads mouth that goes behind his lip doesn't look like it connects to the little chin below the lip. If that made any sense.Your characters from your other posts are looking good too! The more you study, the more solid they will become.
Cheers Joshua! Your studies are looking great too. I just wish I had more time to work on these all the time haha. Tiring stuff but it's got to be done :)