Keen Sight and Smell. The Squared Bear has advantage on Wisdom (Perception) checks that rely on sight or smell.

Squared Form. The Squared Bear is a constantly shifting amalgamation of hair, claws, and teeth.  It is immune to any spell or effect that would alter its form. Creatures that move within 5 feet of the Squared Bear or start their turn there must succeed on a DC 14 Dexterity Saving throw or take 1d6 slashing damage.

Fragile Reality.  The Squared Bear has disadvantage on saving throws to resist being sent to other planes, such as via the banishment spell.

Multiattack. The Squared Bear makes one Bite attack and 1d4 +1 Claw attacks.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 8 (1d10 + 3) piercing damage.

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage.