If you could understand what the heck that walking furball is saying you'd discover that Chewbacca is actually a pretty funny fellow, and that's no small feat considering Wookiees have very little patience for comedy.
Chewie prefers pun based comedy to slapstick or observational humor, and when he gets rolling with those puns there's no stopping him.
Of course, it doesn't hurt that he's a massive creature with fangs and elite combat skills, and even audiences who don't fully appreciate his brand of comedy laugh when he delivers the punny.
Illustrator Joe Stone does a great job of bringing Chewie's puns to life via pen and ink in his series "Drewbacca", which follows in the footsteps of his "Drawntroopers" project. Check 'em out and LOL, or aarrragghuuhw as the case may be.