|XP - Random amount|
|Drop - Fur, Most of the time fish|
|Health - Normal: 12.5|
|Attack - 2 hearts|
|Spawn - Grass (during daytime)|
Bears are similar to Rats in the way they attack - at day, or in high light levels, they are passive, but once they get into a low light level they will become hostile. Bears attack any weak mob they see, like pet Cats. Upon death they drop fur and/or fish (fish being most common), just like Polar Bears. They will fight back when provoked.
Sources - Minecraft Forums