Bubble Guppies (2011)

S5E4 The Good, the Sad, and the Grumpy!

Mr. Grumpfish arrives in Happy Junction, spreading his gloom and causing everyone, including Sheriff Molly, to feel irritable and down. Determined to lift the town's spirits, Sheriff Molly sets out on a mission to help her friends cope with their challenging feelings and restore the joy that once filled their community.