Jack Frost (1934)
The character of Jack Frost is presented as sort of a nature spirit who shows up to paint the changing season and warn all the animals it's time to get in out of the cold. He warns the main character - the aforementioned bear - about Old Man Winter, but the bear's convinced his coat of fur is more than enough to keep him safe. Long story short, Old Man Winter (personified as a creepy ice-man) is a bit tougher than the bear was expecting.
It's not particularly complicated, but it's my favorite of these eight minute shorts so far. Not surprisingly, it's readily available on YouTube, as the embed below suggests. Once again, if you're no fan of old cartoons, this isn't for you.
For those that are, it's kind of awesome.