The concept of "opposite" is subjective and depends on what characteristics you're considering. For example:
* Size: A small animal like a mouse could be considered the opposite of a bear in terms of size.
* Diet: An herbivore like a deer could be considered the opposite of a bear (which is omnivorous but can be primarily carnivorous).
* Habitat: A creature that lives in the water like a dolphin could be considered the opposite of a bear (which lives on land).
Ultimately, there isn't one single animal that's the exact opposite of a bear. It's more about choosing a characteristic and finding an animal that contrasts with the bear in that specific aspect.