Banjo

Keen Smell. The bear has advantage on Wisdom (Perception) checks that rely on smell.
Bond of friendship. Banjo's actions are synchronized with Kazooie's when rolling initiative the both check but the two take the lower score.

Brute:  While Raging  Banjo's attacks deal additional weapon dice. his strenght score is also set to 26

Rage of loss: should Kazooie be defeated Banjo will use Bear Fever as a reaction, goes into a rage, Gains the Brute ability Grows a size larger, gains 4d12+24 Temporary HP

While  raging, other creatures have disadvantage on opportunity attack rolls against Banjo, and he can use the Dash action as a bonus action on his turn. Banjo has a flying speed of 40 ft. Banjo will fall if he end his turn in the air 

Multiattack. The bear makes three attacks: two claw swings and a bite. 47/
While raging Banjo will use his Bear Fever, Two Frenzy and a crunch

Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 15 (2d8 + 6) piercing damage.  target is grappled (escape DC 17)

Crunch. Melee Weapon Attack: +10 to hit, reach 10 ft., one target Hit: 21 (3d8+8)
piercing damage.  target is grappled (escape DC 19)

Claws. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 16 (4d4 + 6) Slashing Damage.

Frenzy. Melee Weapon Attack: +10 to hit, Reach 10ft. one Target Hit: 23 (6d4+8) Slashing Damage 

Roll. Melee Weapon attack: +10, moves up to half it's speed minimum of 10 ft. Up to 2 targets, Hit:  34/42 (6D6+6) bludgeoning damage target is  prone 

Bear Fever: Spell, Wisdom Save DC 17,  If failed the target is Frightened  While frightened the target contracts a confusing condition 

Dodge Roll: When hit with an Attack Banjo can increase their AC by 3, and make a Roll Attack as their reaction.