Seeing a bear in a dream could have different meanings as per Islam depending upon the situation, context, and actions of the bear.
1- According to Ibn Sirin رحمة الله عليه, the greatest dream interpreter of Islam, a bear in a dream represents a dangerous yet stupid enemy. It is almost always a bad omen.
2- Sitting on a bear in a dream means he would be insulted by the King/ruler/government.
3- Killing a bear in a dream means being victorious over an enemy.
4- Eating the meat of a bear in a dream means that the dreamer would be fearful in real life.
5- According to Ibrahim Karmani رحمة الله عليه, catching a female bear in a dream is a sign of getting married to a stupid and unlucky woman.
6- Seeing a male bear entering your house means that a stupid and unlucky person would come to your home.