Happy is the polar opposite of Grumpy, but oddly enough, they never quarrel at all in Snow White! Happy's friends with Dopey, and the two engage in antics together. But Happy sort of keeps Dopey in check. There's that one scene where Dopey is looking under Happy's beard to see if the Queen was hiding under there, and Happy bashed him over the head as if to say, "What are you doing?!"
Happy also gives a really cute performance in "The Silly Song"!
This is the clip where Snow White meets the dwarfs and Happy hits Dopey upside the head.
And here is "The Silly Song" and Happy's performance!