Deadpan Snarker: From Sleep, when he and several other Mr. Men are trying to track down a loud scary noise, thinking it's a monster. They, unsurprisingly, find it's actually Miss. Scary's loud snoring:
Mr. Strong: "Miss. Scary?"
Mr. Nervous: "B-b-but she's no monster!"
Mr. Grumpy: "Well, that depends on how you look at it."
Took a Level in Kindness: In the original books, he yells at everyone (frightning them into doing whatever he wants), and destroys books and flowers just because he doesn't like them, not to mention trying to make Little Miss Sunshine cross note New Little Miss Story Library Little Miss Sunshine Keeps Her Smile just because he doesn't like her being happy; he even assaulted Mr Happy a few times in the books. Here, he's more tolerant of happy people, and instead of yelling or destroying things, is just grumpy and sarcastic.