When he jumps into the scene, it's animated using basic principles but done in a very underplayed way. He antics first, then jumps up and arcs through the air, lands, squashes and recoils up into his final pose.
He's almost floating.
The subtle approach ads to the effect of him being a slow witted naive hick.
Lummox Lip Variations In 1 SceneI like watching Chuck and his animators trying to figure out how to make this design work.
They keep changing his design throughout the scene as they discover funny ways to animate and draw his lips.