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.

Other Traits. The zombie loses any trait, such as Amphibious, that assumes a living physiology. The zombie cannot cast spells and loses all spell slots. At the GM's discretion, traits that would be harmful to undead no longer affect undead.

Undead Nature. A zombie doesn't require air, food, drink, or sleep.

Multiattack. The werebear makes two attacks. 

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) piercing damage. If the target is a humanoid, it must succeed on a DC 14 Constitution saving throw or be cursed with werebear lycanthropy.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.