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

Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Multiattack. The zombie owlbear makes two attacks: one with its beak and one with its claws.

Beak. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 10 (1d10 + 5) piercing damage.

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage.