He speaks in short and simple sentences, and has the I.Q. of a weed-whacker. However, he is the friendliest of the three, as he made good pals with Waffle in "Two of A Kind." This friendship had (temporarily) opened their respective brothers' eyes on the damages their petty battles can cause.
Friendship is a rarity to Lunk, and any that he gets he simply refers to as "Friiieend!" He's buoyant in water and can substitute for a raft. Lunk also has a loud set of vocal chords, a set that can match the volume of a foghorn and can shatter windows. Lunk is like a giant kid, and likes to play, though nobody would play with him (aside from Waffle as of "Two of A Kind").