Bears are one of the enemies on The DOG Island. When you get hurt by a Bear you lose one heart. There is one bear in Green Meadows, and one bear in Gola Highlands. Both bears fall asleep, giving you the chance to scare them with a Bark or a Howl.
When you go into West Chilly Fields and East Chilly Fields, you will encounter Polar Bears, which roam around through a certain path. These bears are more dangerous, as not only that they can see you when you're far away, but because Polar Bears may grab you and spin you around on their bellies (like they're in the Circus), making you lose two and a half hearts. Like normal Bears, they will fall asleep. However, they stay awake longer than the normal Bears.