Winnie the Pooh and a Day for Eeyore (1983)
Eeyore is gloomy, like always, but more so now. His birthday is right around the corner and everybody has forgotten. It didn't cheer him up any when Tigger "accidentally" knocks Eeyore into the river. Pooh invents a new game, "Pooh Sticks", and everyone contributes to Eeyore's party, there's flat balloons, storage honey pots with Owl's hand writing on them, and a game of Pooh Sticks which Tigger claims he likes, but immediately hates it because he lost. It turns out to be a happy birthday celebration after all.