Gruff Character Study

Worked on this character last night, these are more like the original character sketches done with the kids. I am wondering if this guy looks to old and grumpy...instead of more puppy and floppy as last night...I still need to put more of a back story to this guy.  Gruff is a good guy who will be the helpful muscle for my little lost mice in the story.  I need him to be kind but also a tougher side when challenged...more to come